diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2022-02-08 23:37:28 -0800 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2022-02-11 13:26:49 -0800 |
| commit | 5c3c067b601bcbcd381214e3a40e666fda5f3d6f (patch) | |
| tree | f5186bce2f7f40c457e678e0e276cb51a1da85bf | |
| parent | 74b0fe80409733055971bbfaf33c80a33fddeeb3 (diff) | |
| download | linux-5c3c067b601bcbcd381214e3a40e666fda5f3d6f.tar.bz2 | |
cxl/core/port: Fix unregister_port() lock assertion
The device_lock_assert() in unregister_port() fails to pick the right
device leading to splats like the following from:
echo "ACPI0017:00" > /sys/bus/platform/drivers/cxl_acpi/unbind
WARNING: CPU: 32 PID: 1147 at include/linux/device.h:787 unregister_port+0x49/0x50 [cxl_c
[..]
RIP: 0010:unregister_port+0x49/0x50 [cxl_core]
[..]
Call Trace:
<TASK>
release_nodes+0x63/0x80
devres_release_all+0x8b/0xc0
__device_release_driver+0x190/0x240
device_driver_detach+0x3e/0xa0
unbind_store+0x113/0x130
Fix it up to assert on the device_lock() for ACPI0017 for root and 1st
level ports, and parent ports for all the rest.
Fixes: 54cdbf845cf7 ("cxl/port: Add a driver for 'struct cxl_port' objects")
Reported-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Ben Widawsky <ben.widawsky@intel.com>
Link: https://lore.kernel.org/r/164439224893.2941117.18331456248117887720.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| -rw-r--r-- | drivers/cxl/core/port.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index c3e83c624700..9b4bbd51fbaa 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -348,12 +348,28 @@ EXPORT_SYMBOL_NS_GPL(to_cxl_port, CXL); static void unregister_port(void *_port) { struct cxl_port *port = _port; + struct cxl_port *parent; + struct device *lock_dev; - if (!is_cxl_root(port)) { - device_lock_assert(port->dev.parent); - port->uport = NULL; - } + if (is_cxl_root(port)) + parent = NULL; + else + parent = to_cxl_port(port->dev.parent); + + /* + * CXL root port's and the first level of ports are unregistered + * under the platform firmware device lock, all other ports are + * unregistered while holding their parent port lock. + */ + if (!parent) + lock_dev = port->uport; + else if (is_cxl_root(parent)) + lock_dev = parent->uport; + else + lock_dev = &parent->dev; + device_lock_assert(lock_dev); + port->uport = NULL; device_unregister(&port->dev); } |