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2022-11-10driver core: Fix bus_type.match() error handling in __driver_attach()Isaac J. Manjarres1-1/+5
When a driver registers with a bus, it will attempt to match with every device on the bus through the __driver_attach() function. Currently, if the bus_type.match() function encounters an error that is not -EPROBE_DEFER, __driver_attach() will return a negative error code, which causes the driver registration logic to stop trying to match with the remaining devices on the bus. This behavior is not correct; a failure while matching a driver to a device does not mean that the driver won't be able to match and bind with other devices on the bus. Update the logic in __driver_attach() to reflect this. Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()") Cc: stable@vger.kernel.org Cc: Saravana Kannan <saravanak@google.com> Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com> Link: https://lore.kernel.org/r/20220921001414.4046492-1-isaacmanjarres@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-10driver core: mark driver_allows_async_probing staticChristoph Hellwig1-1/+1
driver_allows_async_probing is only used in drivers/base/dd.c, so mark it static and remove the declaration in drivers/base/base.h. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20221030092255.872280-1-hch@lst.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-12Merge 6.0-rc5 into driver-core-nextGreg Kroah-Hartman1-0/+40
We need the driver core and debugfs changes in this branch. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-01driver_core: move from strlcpy with unused retval to strscpyWolfram Sang1-1/+1
Follow the advice of the below link and prefer 'strscpy' in this subsystem. Conversion is 1:1 because the return value is not used. Generated by a coccinelle script. Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/ Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Link: https://lore.kernel.org/r/20220818205956.6528-1-wsa+renesas@sang-engineering.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-01driver core: Don't probe devices after bus_type.match() probe deferralIsaac J. Manjarres1-0/+10
Both __device_attach_driver() and __driver_attach() check the return code of the bus_type.match() function to see if the device needs to be added to the deferred probe list. After adding the device to the list, the logic attempts to bind the device to the driver anyway, as if the device had matched with the driver, which is not correct. If __device_attach_driver() detects that the device in question is not ready to match with a driver on the bus, then it doesn't make sense for the device to attempt to bind with the current driver or continue attempting to match with any of the other drivers on the bus. So, update the logic in __device_attach_driver() to reflect this. If __driver_attach() detects that a driver tried to match with a device that is not ready to match yet, then the driver should not attempt to bind with the device. However, the driver can still attempt to match and bind with other devices on the bus, as drivers can be bound to multiple devices. So, update the logic in __driver_attach() to reflect this. Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()") Cc: stable@vger.kernel.org Cc: Saravana Kannan <saravanak@google.com> Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Saravana Kannan <saravanak@google.com> Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com> Link: https://lore.kernel.org/r/20220817184026.3468620-1-isaacmanjarres@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-23Revert "driver core: Delete driver_deferred_probe_check_state()"Saravana Kannan1-0/+30
This reverts commit 9cbffc7a59561be950ecc675d19a3d2b45202b2b. There are a few more issues to fix that have been reported in the thread for the original series [1]. We'll need to fix those before this will work. So, revert it for now. [1] - https://lore.kernel.org/lkml/20220601070707.3946847-1-saravanak@google.com/ Fixes: 9cbffc7a5956 ("driver core: Delete driver_deferred_probe_check_state()") Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Peng Fan <peng.fan@nxp.com> Tested-by: Douglas Anderson <dianders@chromium.org> Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220819221616.2107893-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-27driver core: fix potential deadlock in __driver_attachZhang Wensheng1-1/+4
In __driver_attach function, There are also AA deadlock problem, like the commit b232b02bf3c2 ("driver core: fix deadlock in __device_attach"). stack like commit b232b02bf3c2 ("driver core: fix deadlock in __device_attach"). list below: In __driver_attach function, The lock holding logic is as follows: ... __driver_attach if (driver_allows_async_probing(drv)) device_lock(dev) // get lock dev async_schedule_dev(__driver_attach_async_helper, dev); // func async_schedule_node async_schedule_node_domain(func) entry = kzalloc(sizeof(struct async_entry), GFP_ATOMIC); /* when fail or work limit, sync to execute func, but __driver_attach_async_helper will get lock dev as will, which will lead to A-A deadlock. */ if (!entry || atomic_read(&entry_count) > MAX_WORK) { func; else queue_work_node(node, system_unbound_wq, &entry->work) device_unlock(dev) As above show, when it is allowed to do async probes, because of out of memory or work limit, async work is not be allowed, to do sync execute instead. it will lead to A-A deadlock because of __driver_attach_async_helper getting lock dev. Reproduce: and it can be reproduce by make the condition (if (!entry || atomic_read(&entry_count) > MAX_WORK)) untenable, like below: [ 370.785650] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 370.787154] task:swapper/0 state:D stack: 0 pid: 1 ppid: 0 flags:0x00004000 [ 370.788865] Call Trace: [ 370.789374] <TASK> [ 370.789841] __schedule+0x482/0x1050 [ 370.790613] schedule+0x92/0x1a0 [ 370.791290] schedule_preempt_disabled+0x2c/0x50 [ 370.792256] __mutex_lock.isra.0+0x757/0xec0 [ 370.793158] __mutex_lock_slowpath+0x1f/0x30 [ 370.794079] mutex_lock+0x50/0x60 [ 370.794795] __device_driver_lock+0x2f/0x70 [ 370.795677] ? driver_probe_device+0xd0/0xd0 [ 370.796576] __driver_attach_async_helper+0x1d/0xd0 [ 370.797318] ? driver_probe_device+0xd0/0xd0 [ 370.797957] async_schedule_node_domain+0xa5/0xc0 [ 370.798652] async_schedule_node+0x19/0x30 [ 370.799243] __driver_attach+0x246/0x290 [ 370.799828] ? driver_allows_async_probing+0xa0/0xa0 [ 370.800548] bus_for_each_dev+0x9d/0x130 [ 370.801132] driver_attach+0x22/0x30 [ 370.801666] bus_add_driver+0x290/0x340 [ 370.802246] driver_register+0x88/0x140 [ 370.802817] ? virtio_scsi_init+0x116/0x116 [ 370.803425] scsi_register_driver+0x1a/0x30 [ 370.804057] init_sd+0x184/0x226 [ 370.804533] do_one_initcall+0x71/0x3a0 [ 370.805107] kernel_init_freeable+0x39a/0x43a [ 370.805759] ? rest_init+0x150/0x150 [ 370.806283] kernel_init+0x26/0x230 [ 370.806799] ret_from_fork+0x1f/0x30 To fix the deadlock, move the async_schedule_dev outside device_lock, as we can see, in async_schedule_node_domain, the parameter of queue_work_node is system_unbound_wq, so it can accept concurrent operations. which will also not change the code logic, and will not lead to deadlock. Fixes: ef0ff68351be ("driver core: Probe devices asynchronously instead of the driver") Signed-off-by: Zhang Wensheng <zhangwensheng5@huawei.com> Link: https://lore.kernel.org/r/20220622074327.497102-1-zhangwensheng5@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10driver core: Delete driver_deferred_probe_check_state()Saravana Kannan1-30/+0
The function is no longer used. So delete it. Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220601070707.3946847-10-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10Revert "driver core: Set default deferred_probe_timeout back to 0."Saravana Kannan1-0/+5
This reverts commit 11f7e7ef553b6b93ac1aa74a3c2011b9cc8aeb61. Let's take another shot at getting deferred_probe_timeout=10 to work. Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220601070707.3946847-7-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10driver core: Add wait_for_init_devices_probe helper functionSaravana Kannan1-5/+14
Some devices might need to be probed and bound successfully before the kernel boot sequence can finish and move on to init/userspace. For example, a network interface might need to be bound to be able to mount a NFS rootfs. With fw_devlink=on by default, some of these devices might be blocked from probing because they are waiting on a optional supplier that doesn't have a driver. While fw_devlink will eventually identify such devices and unblock the probing automatically, it might be too late by the time it unblocks the probing of devices. For example, the IP4 autoconfig might timeout before fw_devlink unblocks probing of the network interface. This function is available to temporarily try and probe all devices that have a driver even if some of their suppliers haven't been added or don't have drivers. The drivers can then decide which of the suppliers are optional vs mandatory and probe the device if possible. By the time this function returns, all such "best effort" probes are guaranteed to be completed. If a device successfully probes in this mode, we delete all fw_devlink discovered dependencies of that device where the supplier hasn't yet probed successfully because they have to be optional dependencies. This also means that some devices that aren't needed for init and could have waited for their optional supplier to probe (when the supplier's module is loaded later on) would end up probing prematurely with limited functionality. So call this function only when boot would fail without it. Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220601070707.3946847-5-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-03driver core: Set default deferred_probe_timeout back to 0.Saravana Kannan1-5/+0
Since we had to effectively reverted commit 35a672363ab3 ("driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires") in an earlier patch, a non-zero deferred_probe_timeout will break NFS rootfs mounting [1] again. So, set the default back to zero until we can fix that. [1] - https://lore.kernel.org/lkml/TYAPR01MB45443DF63B9EF29054F7C41FD8C60@TYAPR01MB4544.jpnprd01.prod.outlook.com/ Fixes: 2b28a1a84a0e ("driver core: Extend deferred probe timeout on driver registration") Cc: Mark Brown <broonie@kernel.org> Cc: Rob Herring <robh@kernel.org> Reported-by: Nathan Chancellor <nathan@kernel.org> Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220526034609.480766-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-06-03driver core: Fix wait_for_device_probe() & deferred_probe_timeout interactionSaravana Kannan1-5/+0
Mounting NFS rootfs was timing out when deferred_probe_timeout was non-zero [1]. This was because ip_auto_config() initcall times out waiting for the network interfaces to show up when deferred_probe_timeout was non-zero. While ip_auto_config() calls wait_for_device_probe() to make sure any currently running deferred probe work or asynchronous probe finishes, that wasn't sufficient to account for devices being deferred until deferred_probe_timeout. Commit 35a672363ab3 ("driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires") tried to fix that by making sure wait_for_device_probe() waits for deferred_probe_timeout to expire before returning. However, if wait_for_device_probe() is called from the kernel_init() context: - Before deferred_probe_initcall() [2], it causes the boot process to hang due to a deadlock. - After deferred_probe_initcall() [3], it blocks kernel_init() from continuing till deferred_probe_timeout expires and beats the point of deferred_probe_timeout that's trying to wait for userspace to load modules. Neither of this is good. So revert the changes to wait_for_device_probe(). [1] - https://lore.kernel.org/lkml/TYAPR01MB45443DF63B9EF29054F7C41FD8C60@TYAPR01MB4544.jpnprd01.prod.outlook.com/ [2] - https://lore.kernel.org/lkml/YowHNo4sBjr9ijZr@dev-arch.thelio-3990X/ [3] - https://lore.kernel.org/lkml/Yo3WvGnNk3LvLb7R@linutronix.de/ Fixes: 35a672363ab3 ("driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires") Cc: John Stultz <jstultz@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Cc: Basil Eljuse <Basil.Eljuse@arm.com> Cc: Ferry Toth <fntoth@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: linux-pm@vger.kernel.org Reported-by: Nathan Chancellor <nathan@kernel.org> Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: John Stultz <jstultz@google.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220526034609.480766-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-06-03Merge tag 'driver-core-5.19-rc1' of ↵Linus Torvalds1-7/+37
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the set of driver core changes for 5.19-rc1. Lots of tiny driver core changes and cleanups happened this cycle, but the two major things are: - firmware_loader reorganization and additions including the ability to have XZ compressed firmware images and the ability for userspace to initiate the firmware load when it needs to, instead of being always initiated by the kernel. FPGA devices specifically want this ability to have their firmware changed over the lifetime of the system boot, and this allows them to work without having to come up with yet-another-custom-uapi interface for loading firmware for them. - physical location support added to sysfs so that devices that know this information, can tell userspace where they are located in a common way. Some ACPI devices already support this today, and more bus types should support this in the future. Smaller changes include: - driver_override api cleanups and fixes - error path cleanups and fixes - get_abi script fixes - deferred probe timeout changes. It's that last change that I'm the most worried about. It has been reported to cause boot problems for a number of systems, and I have a tested patch series that resolves this issue. But I didn't get it merged into my tree before 5.18-final came out, so it has not gotten any linux-next testing. I'll send the fixup patches (there are 2) as a follow-on series to this pull request. All have been tested in linux-next for weeks, with no reported issues other than the above-mentioned boot time-outs" * tag 'driver-core-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits) driver core: fix deadlock in __device_attach kernfs: Separate kernfs_pr_cont_buf and rename_lock. topology: Remove unused cpu_cluster_mask() driver core: Extend deferred probe timeout on driver registration MAINTAINERS: add Russ Weight as a firmware loader maintainer driver: base: fix UAF when driver_attach failed test_firmware: fix end of loop test in upload_read_show() driver core: location: Add "back" as a possible output for panel driver core: location: Free struct acpi_pld_info *pld driver core: Add "*" wildcard support to driver_async_probe cmdline param driver core: location: Check for allocations failure arch_topology: Trace the update thermal pressure kernfs: Rename kernfs_put_open_node to kernfs_unlink_open_file. export: fix string handling of namespace in EXPORT_SYMBOL_NS rpmsg: use local 'dev' variable rpmsg: Fix calling device_lock() on non-initialized device firmware_loader: describe 'module' parameter of firmware_upload_register() firmware_loader: Move definitions from sysfs_upload.h to sysfs.h firmware_loader: Fix configs for sysfs split selftests: firmware: Add firmware upload selftests ...
2022-05-19driver core: fix deadlock in __device_attachZhang Wensheng1-1/+4
In __device_attach function, The lock holding logic is as follows: ... __device_attach device_lock(dev) // get lock dev async_schedule_dev(__device_attach_async_helper, dev); // func async_schedule_node async_schedule_node_domain(func) entry = kzalloc(sizeof(struct async_entry), GFP_ATOMIC); /* when fail or work limit, sync to execute func, but __device_attach_async_helper will get lock dev as well, which will lead to A-A deadlock. */ if (!entry || atomic_read(&entry_count) > MAX_WORK) { func; else queue_work_node(node, system_unbound_wq, &entry->work) device_unlock(dev) As shown above, when it is allowed to do async probes, because of out of memory or work limit, async work is not allowed, to do sync execute instead. it will lead to A-A deadlock because of __device_attach_async_helper getting lock dev. To fix the deadlock, move the async_schedule_dev outside device_lock, as we can see, in async_schedule_node_domain, the parameter of queue_work_node is system_unbound_wq, so it can accept concurrent operations. which will also not change the code logic, and will not lead to deadlock. Fixes: 765230b5f084 ("driver-core: add asynchronous probing support for drivers") Signed-off-by: Zhang Wensheng <zhangwensheng5@huawei.com> Link: https://lore.kernel.org/r/20220518074516.1225580-1-zhangwensheng5@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-19driver core: Extend deferred probe timeout on driver registrationSaravana Kannan1-0/+19
The deferred probe timer that's used for this currently starts at late_initcall and runs for driver_deferred_probe_timeout seconds. The assumption being that all available drivers would be loaded and registered before the timer expires. This means, the driver_deferred_probe_timeout has to be pretty large for it to cover the worst case. But if we set the default value for it to cover the worst case, it would significantly slow down the average case. For this reason, the default value is set to 0. Also, with CONFIG_MODULES=y and the current default values of driver_deferred_probe_timeout=0 and fw_devlink=on, devices with missing drivers will cause their consumer devices to always defer their probes. This is because device links created by fw_devlink defer the probe even before the consumer driver's probe() is called. Instead of a fixed timeout, if we extend an unexpired deferred probe timer on every successful driver registration, with the expectation more modules would be loaded in the near future, then the default value of driver_deferred_probe_timeout only needs to be as long as the worst case time difference between two consecutive module loads. So let's implement that and set the default value to 10 seconds when CONFIG_MODULES=y. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Rob Herring <robh@kernel.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Will Deacon <will@kernel.org> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Kevin Hilman <khilman@kernel.org> Cc: Thierry Reding <treding@nvidia.com> Cc: Mark Brown <broonie@kernel.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Cc: Paul Kocialkowski <paul.kocialkowski@bootlin.com> Cc: linux-gpio@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: iommu@lists.linux-foundation.org Reviewed-by: Mark Brown <broonie@kernel.org> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220429220933.1350374-1-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-19driver core: Add "*" wildcard support to driver_async_probe cmdline paramSaravana Kannan1-1/+8
There's currently no way to use driver_async_probe kernel cmdline param to enable default async probe for all drivers. So, add support for "*" to match with all driver names. When "*" is used, all other drivers listed in driver_async_probe are drivers that will NOT match the "*". For example: * driver_async_probe=drvA,drvB,drvC drvA, drvB and drvC do asynchronous probing. * driver_async_probe=* All drivers do asynchronous probing except those that have set PROBE_FORCE_SYNCHRONOUS flag. * driver_async_probe=*,drvA,drvB,drvC All drivers do asynchronous probing except drvA, drvB, drvC and those that have set PROBE_FORCE_SYNCHRONOUS flag. Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Feng Tang <feng.tang@intel.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220504005344.117803-1-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-02Merge 5.18-rc5 into driver-core-nextGreg Kroah-Hartman1-0/+1
We need the kernfs/driver core fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-28driver core: Add dma_cleanup callback in bus_typeLu Baolu1-0/+5
The bus_type structure defines dma_configure() callback for bus drivers to configure DMA on the devices. This adds the paired dma_cleanup() callback and calls it during driver unbinding so that bus drivers can do some cleanup work. One use case for this paired DMA callbacks is for the bus driver to check for DMA ownership conflicts during driver binding, where multiple devices belonging to a same IOMMU group (the minimum granularity of isolation and protection) may be assigned to kernel drivers or user space respectively. Without this change, for example, the vfio driver has to listen to a bus BOUND_DRIVER event and then BUG_ON() in case of dma ownership conflict. This leads to bad user experience since careless driver binding operation may crash the system if the admin overlooks the group restriction. Aside from bad design, this leads to a security problem as a root user, even with lockdown=integrity, can force the kernel to BUG. With this change, the bus driver could check and set the DMA ownership in driver binding process and fail on ownership conflicts. The DMA ownership should be released during driver unbinding. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/20220418005000.897664-3-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2022-04-27driver core: Prevent overriding async driver of a device before it probeMark-PK Tsai1-1/+2
When there are 2 matched drivers for a device using async probe mechanism, the dev->p->async_driver might be overridden by the last attached driver. So just skip the later one if the previous matched driver was not handled by async thread yet. Below is my use case which having this problem. Make both driver mmcblk and mmc_test allow async probe, the dev->p->async_driver will be overridden by the later driver mmc_test and bind to the device then claim it for testing. When it happen, mmcblk will never do probe again. Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Link: https://lore.kernel.org/r/20220316074328.1801-1-mark-pk.tsai@mediatek.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26Documentation: dd: Use ReST lists for return values of ↵Bagas Sanjaya1-4/+4
driver_deferred_probe_check_state() Sphinx reported build warnings mentioning drivers/base/dd.c: </path/to/linux>/Documentation/driver-api/infrastructure:35: ./drivers/base/dd.c:280: WARNING: Unexpected indentation. </path/to/linux>/Documentation/driver-api/infrastructure:35: ./drivers/base/dd.c:281: WARNING: Block quote ends without a blank line; unexpected unindent. The warnings above is due to syntax error in the "Return" section of driver_deferred_probe_check_state() which messed up with desired line breaks. Fix the issue by using ReST lists syntax. Fixes: c8c43cee29f6ca ("driver core: Fix driver_deferred_probe_check_state() logic") Cc: linux-pm@vger.kernel.org Cc: stable@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Thierry Reding <treding@nvidia.com> Cc: Mark Brown <broonie@kernel.org> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Todd Kjos <tkjos@google.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Kevin Hilman <khilman@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Rob Herring <robh@kernel.org> Cc: John Stultz <john.stultz@linaro.org> Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Link: https://lore.kernel.org/r/20220416071137.19512-1-bagasdotme@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08net: mdio: don't defer probe forever if PHY IRQ provider is missingVladimir Oltean1-0/+1
When a driver for an interrupt controller is missing, of_irq_get() returns -EPROBE_DEFER ad infinitum, causing fwnode_mdiobus_phy_device_register(), and ultimately, the entire of_mdiobus_register() call, to fail. In turn, any phy_connect() call towards a PHY on this MDIO bus will also fail. This is not what is expected to happen, because the PHY library falls back to poll mode when of_irq_get() returns a hard error code, and the MDIO bus, PHY and attached Ethernet controller work fine, albeit suboptimally, when the PHY library polls for link status. However, -EPROBE_DEFER has special handling given the assumption that at some point probe deferral will stop, and the driver for the supplier will kick in and create the IRQ domain. Reasons for which the interrupt controller may be missing: - It is not yet written. This may happen if a more recent DT blob (with an interrupt-parent for the PHY) is used to boot an old kernel where the driver didn't exist, and that kernel worked with the vintage-correct DT blob using poll mode. - It is compiled out. Behavior is the same as above. - It is compiled as a module. The kernel will wait for a number of seconds specified in the "deferred_probe_timeout" boot parameter for user space to load the required module. The current default is 0, which times out at the end of initcalls. It is possible that this might cause regressions unless users adjust this boot parameter. The proposed solution is to use the driver_deferred_probe_check_state() helper function provided by the driver core, which gives up after some -EPROBE_DEFER attempts, taking "deferred_probe_timeout" into consideration. The return code is changed from -EPROBE_DEFER into -ENODEV or -ETIMEDOUT, depending on whether the kernel is compiled with support for modules or not. Fixes: 66bdede495c7 ("of_mdio: Fix broken PHY IRQ in case of probe deferral") Suggested-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/20220407165538.4084809-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-18drivers/base/dd.c : Remove the initial value of the global variablelizhe1-1/+1
The global variable driver_deferred_probe_enable has a default value of false and does not need to be initialized to false. Signed-off-by: lizhe <sensor1010@163.com> Link: https://lore.kernel.org/r/20220309135418.31101-1-sensor1010@163.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-18driver core: dd: fix return value of __setup handlerRandy Dunlap1-1/+1
When "driver_async_probe=nulltty" is used on the kernel boot command line, it causes an Unknown parameter message and the string is added to init's environment strings, polluting them. Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc6 driver_async_probe=nulltty", will be passed to user space. Run /sbin/init as init process with arguments: /sbin/init with environment: HOME=/ TERM=linux BOOT_IMAGE=/boot/bzImage-517rc6 driver_async_probe=nulltty Change the return value of the __setup function to 1 to indicate that the __setup option has been handled. Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Fixes: 1ea61b68d0f8 ("async: Add cmdline option to specify drivers to be async probed") Cc: Feng Tang <feng.tang@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru> Reviewed-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20220301041829.15137-1-rdunlap@infradead.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-18driver core: Refactor sysfs and drv/bus remove hooksRob Herring1-20/+14
There are 3 copies of the same device sysfs cleanup and drv/bus remove() hooks used for probe failure, testing re-probing, and device unbinding. Let's refactor the code to its own function. Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20220223225257.1681968-3-robh@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-18driver core: Refactor multiple copies of device cleanupRob Herring1-30/+16
There are 3 copies of the same device cleanup code used for probe failure, testing re-probing, and device unbinding. Changes to this code often miss at least one of the copies of the code. See commits d0243bbd5dd3 ("drivers core: Free dma_range_map when driver probe failed") and d8f7a5484f21 ("driver core: Free DMA range map when device is released") for example. Let's refactor the code to its own function. Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20220223225257.1681968-2-robh@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-28Merge 5.17-rc6 into driver-core-nextGreg Kroah-Hartman1-0/+5
We need the driver core fix in here as well for future changes. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-22driver core: Free DMA range map when device is releasedMårten Lindahl1-0/+5
When unbinding/binding a driver with DMA mapped memory, the DMA map is not freed before the driver is reloaded. This leads to a memory leak when the DMA map is overwritten when reprobing the driver. This can be reproduced with a platform driver having a dma-range: dummy { ... #address-cells = <0x2>; #size-cells = <0x2>; ranges; dma-ranges = <...>; ... }; and then unbinding/binding it: ~# echo soc:dummy >/sys/bus/platform/drivers/<driver>/unbind DMA map object 0xffffff800b0ae540 still being held by &pdev->dev ~# echo soc:dummy >/sys/bus/platform/drivers/<driver>/bind ~# echo scan > /sys/kernel/debug/kmemleak ~# cat /sys/kernel/debug/kmemleak unreferenced object 0xffffff800b0ae540 (size 64): comm "sh", pid 833, jiffies 4295174550 (age 2535.352s) hex dump (first 32 bytes): 00 00 00 80 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 80 00 00 00 00 00 00 00 80 00 00 00 00 ................ backtrace: [<ffffffefd1694708>] create_object.isra.0+0x108/0x344 [<ffffffefd1d1a850>] kmemleak_alloc+0x8c/0xd0 [<ffffffefd167e2d0>] __kmalloc+0x440/0x6f0 [<ffffffefd1a960a4>] of_dma_get_range+0x124/0x220 [<ffffffefd1a8ce90>] of_dma_configure_id+0x40/0x2d0 [<ffffffefd198b68c>] platform_dma_configure+0x5c/0xa4 [<ffffffefd198846c>] really_probe+0x8c/0x514 [<ffffffefd1988990>] __driver_probe_device+0x9c/0x19c [<ffffffefd1988cd8>] device_driver_attach+0x54/0xbc [<ffffffefd1986634>] bind_store+0xc4/0x120 [<ffffffefd19856e0>] drv_attr_store+0x30/0x44 [<ffffffefd173c9b0>] sysfs_kf_write+0x50/0x60 [<ffffffefd173c1c4>] kernfs_fop_write_iter+0x124/0x1b4 [<ffffffefd16a013c>] new_sync_write+0xdc/0x160 [<ffffffefd16a256c>] vfs_write+0x23c/0x2a0 [<ffffffefd16a2758>] ksys_write+0x64/0xec To prevent this we should free the dma_range_map when the device is released. Fixes: e0d072782c73 ("dma-mapping: introduce DMA range map, supplanting dma_pfn_offset") Cc: stable <stable@vger.kernel.org> Suggested-by: Rob Herring <robh@kernel.org> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Mårten Lindahl <marten.lindahl@axis.com> Link: https://lore.kernel.org/r/20220216094128.4025861-1-marten.lindahl@axis.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-22driver core: cleanup double words commentsTom Rix1-2/+2
Remove the second 'are' and 'the'. Signed-off-by: Tom Rix <trix@redhat.com> Link: https://lore.kernel.org/r/20220212143233.2648872-1-trix@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-06driver core: Make bus notifiers in right order in really_probe()Lu Baolu1-1/+1
If a driver cannot be bound to a device, the correct bus notifier order should be: - BUS_NOTIFY_BIND_DRIVER: driver is about to be bound - BUS_NOTIFY_DRIVER_NOT_BOUND: driver failed to be bound or no notifier if the failure happens before the actual binding. The really_probe() notifies a BUS_NOTIFY_DRIVER_NOT_BOUND event without a BUS_NOTIFY_BIND_DRIVER if .dma_configure() returns failure. This change makes the notifiers in order. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/20211231033901.2168664-3-baolu.lu@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-06driver core: Move driver_sysfs_remove() after driver_sysfs_add()Lu Baolu1-3/+4
The driver_sysfs_remove() should be called after driver_sysfs_add() in really_probe(). The out-of-order driver_sysfs_remove() tries to remove some nonexistent nodes under the device and driver sysfs nodes. This is allowed, hence this change doesn't fix any problem, just a cleanup. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/20211231033901.2168664-2-baolu.lu@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-09Merge 5.14-rc5 into driver-core-nextGreg Kroah-Hartman1-2/+2
We need the driver core fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-27drivers core: Fix oops when driver probe failsFilip Schauer1-2/+2
dma_range_map is freed to early, which might cause an oops when a driver probe fails. Call trace: is_free_buddy_page+0xe4/0x1d4 __free_pages+0x2c/0x88 dma_free_contiguous+0x64/0x80 dma_direct_free+0x38/0xb4 dma_free_attrs+0x88/0xa0 dmam_release+0x28/0x34 release_nodes+0x78/0x8c devres_release_all+0xa8/0x110 really_probe+0x118/0x2d0 __driver_probe_device+0xc8/0xe0 driver_probe_device+0x54/0xec __driver_attach+0xe0/0xf0 bus_for_each_dev+0x7c/0xc8 driver_attach+0x30/0x3c bus_add_driver+0x17c/0x1c4 driver_register+0xc0/0xf8 __platform_driver_register+0x34/0x40 ... This issue is introduced by commit d0243bbd5dd3 ("drivers core: Free dma_range_map when driver probe failed"). It frees dma_range_map before the call to devres_release_all, which is too early. The solution is to free dma_range_map only after devres_release_all. Fixes: d0243bbd5dd3 ("drivers core: Free dma_range_map when driver probe failed") Cc: stable <stable@vger.kernel.org> Signed-off-by: Filip Schauer <filip@mg6.at> Link: https://lore.kernel.org/r/20210727112311.GA7645@DESKTOP-E8BN1B0.localdomain Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-21driver core: Fix error return code in really_probe()Zhen Lei1-6/+10
In the case of error handling, the error code returned by the subfunction should be propagated instead of 0. Fixes: 1901fb2604fb ("Driver core: fix "driver" symlink timing") Fixes: 23b6904442d0 ("driver core: add dev_groups to all drivers") Fixes: 8fd456ec0cf0 ("driver core: Add state_synced sysfs file for devices that support it") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Link: https://lore.kernel.org/r/20210707074301.2722-1-thunder.leizhen@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-21driver core: Export device_driver_attach()Jason Gunthorpe1-0/+3
This is intended as a replacement API for device_bind_driver(). It has at least the following benefits: - Internal locking. Few of the users of device_bind_driver() follow the locking rules - Calls device driver probe() internally. Notably this means that devm support for probe works correctly as probe() error will call devres_release_all() - struct device_driver -> dev_groups is supported - Simplified calling convention, no need to manually call probe(). The general usage is for situations that already know what driver to bind and need to ensure the bind is synchronized with other logic. Call device_driver_attach() after device_add(). If probe() returns a failure then this will be preserved up through to the error return of device_driver_attach(). Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20210617142218.1877096-6-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-06-21driver core: Don't return EPROBE_DEFER to userspace during sysfs bindChristoph Hellwig1-39/+45
EPROBE_DEFER is an internal kernel error code and it should not be leaked to userspace via the bind_store() sysfs. Userspace doesn't have this constant and cannot understand it. Further, it doesn't really make sense to have userspace trigger a deferred probe via bind_store(), which could eventually succeed, while simultaneously returning an error back. Resolve this by splitting driver_probe_device so that the version used by the sysfs binding that turns EPROBE_DEFER into -EAGAIN, while the one used for internally binding keeps the error code, and calls driver_deferred_probe_add where needed. This also allows to nicely split out the defer_all_probes / probe_count checks so that they actually allow for full device_{block,unblock}_probing protection while not bothering the sysfs bind case. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20210617142218.1877096-5-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-06-21driver core: Flow the return code from ->probe() through to sysfs bindChristoph Hellwig1-9/+20
Currently really_probe() returns 1 on success and 0 if the probe() call fails. This return code arrangement is designed to be useful for __device_attach_driver() which is walking the device list and trying every driver. 0 means to keep trying. However, it is not useful for the other places that call through to really_probe() that do actually want to see the probe() return code. For instance bind_store() would be better to return the actual error code from the driver's probe method, not discarding it and returning -ENODEV. Reorganize things so that really_probe() returns the error code from ->probe as a (inverted) positive number, and 0 for successful attach. With this, __device_attach_driver can ignore the (positive) probe errors, return 1 to exit the loop for a successful binding and pass on the other negative errors, while device_driver_attach simplify inverts the positive errors and returns all errors to the sysfs code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Link: https://lore.kernel.org/r/20210617142218.1877096-4-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-06-21driver core: Better distinguish probe errors in really_probeChristoph Hellwig1-30/+42
really_probe tries to special case errors from ->probe, but due to all other initialization added to the function over time now a lot of internal errors hit that code path as well. Untangle that by adding a new probe_err local variable and apply the special casing only to that. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Link: https://lore.kernel.org/r/20210617142218.1877096-3-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-06-21driver core: Pull required checks into driver_probe_device()Jason Gunthorpe1-22/+10
Checking if the dev is dead or if the dev is already bound is a required precondition to invoking driver_probe_device(). All the call chains leading here duplicate these checks. Add it directly to driver_probe_device() so the precondition is clear and remove the checks from device_driver_attach() and __driver_attach_async_helper(). The other call chain going through __device_attach_driver() does have these same checks but they are inlined into logic higher up the call stack and can't be removed. The sysfs uAPI call chain starting at bind_store() is a bit confused because it reads dev->driver unlocked and returns -ENODEV if it is !NULL, otherwise it reads it again under lock and returns 0 if it is !NULL. Fix this to always return -EBUSY and always read dev->driver under its lock. Done in preparation for the next patches which will add additional callers to driver_probe_device() and will need these checks as well. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> [hch: drop the extra checks in device_driver_attach and bind_store] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Link: https://lore.kernel.org/r/20210617142218.1877096-2-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-14Merge tag 'v5.12-rc7' into driver-core-nextGreg Kroah-Hartman1-3/+5
We need the driver core fix in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-05driver core: add helper for deferred probe reason settingAhmad Fatoum1-6/+11
We now have three places within the same file doing the same operation of freeing this pointer and setting it anew. A helper makes this arguably easier to read, so add one. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Link: https://lore.kernel.org/r/20210323153714.25120-2-a.fatoum@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-05driver core: Improve fw_devlink & deferred_probe_timeout interactionSaravana Kannan1-0/+5
deferred_probe_timeout kernel commandline parameter allows probing of consumer devices if the supplier devices don't have any drivers. fw_devlink=on will indefintely block probe() calls on a device if all its suppliers haven't probed successfully. This completely skips calls to driver_deferred_probe_check_state() since that's only called when a .probe() function calls framework APIs. So fw_devlink=on breaks deferred_probe_timeout. deferred_probe_timeout in its current state also ignores a lot of information that's now available to the kernel. It assumes all suppliers that haven't probed when the timer expires (or when initcalls are done on a static kernel) will never probe and fails any calls to acquire resources from these unprobed suppliers. However, this assumption by deferred_probe_timeout isn't true under many conditions. For example: - If the consumer happens to be before the supplier in the deferred probe list. - If the supplier itself is waiting on its supplier to probe. This patch fixes both these issues by relaxing device links between devices only if the supplier doesn't have any driver that could match with (NOT bound to) the supplier device. This way, we only fail attempts to acquire resources from suppliers that truly don't have any driver vs suppliers that just happen to not have probed yet. Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210402040342.2944858-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-05driver core: Fix locking bug in deferred_probe_timeout_work_func()Saravana Kannan1-3/+5
list_for_each_entry_safe() is only useful if we are deleting nodes in a linked list within the loop. It doesn't protect against other threads adding/deleting nodes to the list in parallel. We need to grab deferred_probe_mutex when traversing the deferred_probe_pending_list. Cc: stable@vger.kernel.org Fixes: 25b4e70dcce9 ("driver core: allow stopping deferred probe after init") Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210402040342.2944858-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-05Merge 5.12-rc6 into driver-core-nextGreg Kroah-Hartman1-0/+3
We need the driver core fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-28base: dd: fix error return code of driver_sysfs_add()Jia-Ju Bai1-2/+5
When device_create_file() fails and returns a non-zero value, no error return code of driver_sysfs_add() is assigned. To fix this bug, ret is assigned with the return value of device_create_file(), and then ret is checked. Reported-by: TOTE Robot <oslab@tsinghua.edu.cn> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Link: https://lore.kernel.org/r/20210324023405.12465-1-baijiaju1990@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-28driver core: Use unbound workqueue for deferred probesYogesh Lal1-1/+1
Deferred probe usually runs only on pinned kworkers, which might take longer time if a device contains multiple sub-devices. One such case is of sound card on mobile devices, where we have good number of mixers and controls per mixer. We observed boot up improvement - deferred probes take ~600ms when bound to little core kworker and ~200ms when deferred probe is queued on unbound wq. This is due to scheduler moving the worker running deferred probe work to big CPUs. Without this change, we see the worker is running on LITTLE CPU due to affinity. Since kworker runs deferred probe of several devices, the locality may not be important. Also, init thread executing driver initcalls, can potentially migrate as it has cpu affinity set to all cpus.In addition to this, async probes use unbounded workqueue. So, using unbounded wq for deferred probes looks to be similar to these w.r.t. scheduling behavior. Signed-off-by: Yogesh Lal <ylal@codeaurora.org> Link: https://lore.kernel.org/r/1616583698-6398-1-git-send-email-ylal@codeaurora.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-23driver core: clear deferred probe reason on probe retryAhmad Fatoum1-0/+3
When retrying a deferred probe, any old defer reason string should be discarded. Otherwise, if the probe is deferred again at a different spot, but without setting a message, the now incorrect probe reason will remain. This was observed with the i.MX I2C driver, which ultimately failed to probe due to lack of the GPIO driver. The probe defer for GPIO doesn't record a message, but a previous probe defer to clock_get did. This had the effect that /sys/kernel/debug/devices_deferred listed a misleading probe deferral reason. Cc: stable <stable@vger.kernel.org> Fixes: d090b70ede02 ("driver core: add deferring probe reason to devices_deferred property") Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Link: https://lore.kernel.org/r/20210319110459.19966-1-a.fatoum@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-23driver core: Update device link status properly for device_bind_driver()Saravana Kannan1-1/+3
Device link status was not getting updated correctly when device_bind_driver() is called on a device. This causes a warning[1]. Fix this by updating device links that can be updated and dropping device links that can't be updated to a sensible state. [1] - https://lore.kernel.org/lkml/56f7d032-ba5a-a8c7-23de-2969d98c527e@nvidia.com/ Tested-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210302211133.2244281-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-23driver core: Avoid pointless deferred probe attemptsSaravana Kannan1-0/+6
There's no point in adding a device to the deferred probe list if we know for sure that it doesn't have a matching driver. So, check if a device can match with a driver before adding it to the deferred probe list. Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210302211133.2244281-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-23driver core: dd: remove deferred_devices variableGreg Kroah-Hartman1-4/+3
No need to save the debugfs dentry for the "devices_deferred" debugfs file (gotta love the juxtaposition), if we need to remove it we can look it up from debugfs itself. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: linux-kernel@vger.kernel.org Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/20210216142400.3759099-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-12Revert "driver core: Reorder devices on successful probe"Greg Kroah-Hartman1-7/+0
This reverts commit 5b6164d3465fcc13b5679c860c452963443172a7. Stephan reports problems with this commit, so revert it for now. Fixes: 5b6164d3465f ("driver core: Reorder devices on successful probe") Link: https://lore.kernel.org/r/X/ycQpu7NIGI969v@gerhold.net Reported-by: Stephan Gerhold <stephan@gerhold.net> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Rafael. J. Wysocki <rafael@kernel.org> Cc: Thierry Reding <treding@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>