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2014-05-21can: peak_pci: prevent use after free at netdev removalStephane Grosjean1-5/+9
As remarked by Christopher R. Baker in his post at http://marc.info/?l=linux-can&m=139707295706465&w=2 there's a possibility for an use after free condition at device removal. This simplified patch introduces an additional variable to prevent the issue. Thanks for catching this. Cc: linux-stable <stable@vger.kernel.org> Reported-by: Christopher R. Baker <cbaker@rec.ri.cmu.edu> Signed-off-by: Stephane Grosjean <s.grosjean@peak-system.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-05-19can: c_can: remove obsolete STRICT_FRAME_ORDERING Kconfig optionOliver Hartkopp2-43/+0
In 2b9aecdce2 ("can: c_can: Disable rx split as workaround") a new Kconfig option was introduced as a workaround. The tests performed by Alexander Stein confirmed this option to be obsolete with all the other cleanups and fixes that had been discussed that time: http://marc.info/?l=linux-can&m=139746476821294&w=2 Both (author and tester) agreed to remove this Kconfig option again: http://marc.info/?l=linux-can&m=139883820714229&w=2 As some more cleanups took place since then a simple revert is not possible. This patch removes the entire option as it would behave when disabled. Further beautification’s can be done later. Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: slcan: Fix spinlock variantAlexander Stein1-3/+3
slc_xmit is called within softirq context and locks sl->lock, but slcan_write_wakeup is not softirq context, so we need to use spin_[un]lock_bh! Detected using kernel lock debugging mechanism. Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Acked-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: fix return value from can_get_bittiming()Oliver Hartkopp1-1/+1
When trying to set a data bitrate on non CAN FD devices the 'ip' tool answers with: RTNETLINK answers: Unknown error 524 Rename '-ENOTSUPP' to '-EOPNOTSUPP' so that 'ip' answers correctly: RTNETLINK answers: Operation not supported Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: sja1000_isa: add locking for indirect register access modeOliver Hartkopp1-3/+13
When accessing the SJA1000 controller registers in the indirect access mode, writing the register number and reading/writing the data has to be an atomic attempt. As the sja1000_isa driver is an old style driver with a fixed number of instances the locking variable depends on the same index like all the other configuration elements given on the module command line. As a positive side effect dev->dev_id is populated by the instance index, which was missing in 3e66d0138c05d9 ("can: populate netdev::dev_id for udev discrimination"). Reported-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can_pci: enable PCI bus master only for MSIWolfgang Grandegger1-2/+5
Coverity complains that c_can_pci_probe() calls pci_enable_msi() without checking the result: CID 712278 (#1 of 1): Unchecked return value (CHECKED_RETURN) 3. check_return: Calling pci_enable_msi_block without checking return value (as is done elsewhere 88 out of 105 times). 88 pci_enable_msi(pdev); This is CID 712278. Signed-off-by: Wolfgang Grandegger <wg@grandegger.com> Reported-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: use proper type for 'instance'Wolfram Sang2-2/+2
Commit 6439fbce1075 (can: c_can: fix error checking of priv->instance in probe()) found the warning but applied a suboptimal solution. Since, both pdev->id and of_alias_get_id() return integers, it makes sense to convert the variable to an integer and avoid the cast. Signed-off-by: Wolfram Sang <wsa@sang-engineering.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Speed up tx buffer invalidationThomas Gleixner2-15/+40
It's suffcient to kill the TXIE bit in the message control register even if the documentation of C and D CAN says that it's not allowed to do that while MSGVAL is set. Reality tells a different story and this change gives us another 2% of CPU back for not waiting on I/O. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Remove tx lockingThomas Gleixner2-92/+43
Mark suggested to use one IF for the softirq and the other for the xmit function to avoid the xmit lock. That requires to write the frame into the interface first, then handle the echo skb and store the dlc before committing the TX request to the message ram. We use an atomic to handle the active buffers instead of reading the MSGVAL register as thats way faster especially on PCH/x86. Suggested-by: Mark <mark5@del-llc.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Use proper u32 variables in c_can_write_msg_object()Thomas Gleixner1-9/+9
Instead of obfuscating the code by artificial 16 bit splits use the proper 32 bit assignments and split the result when writing to the interface. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Cleanup c_can_write_msg_object()Thomas Gleixner2-33/+24
Remove the MASK from the TX transfer side. Make the code readable and get rid of the annoying IFX_WRITE_XXX_16BIT macros which are just obfuscating the code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Cleanup c_can_msg_obj_put/get()Thomas Gleixner1-44/+16
Sigh! Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Cleanup c_can_inval_msg_object()Thomas Gleixner1-5/+5
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Cleanup setup of receive buffersThomas Gleixner1-21/+17
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Cleanup c_can_read_msg_object()Thomas Gleixner1-17/+15
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Cleanup irq enable/disableThomas Gleixner1-25/+12
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Work around C_CAN RX wreckageThomas Gleixner2-3/+11
Alexander reported that the new optimized handling of the RX fifo causes random packet loss on Intel PCH C_CAN hardware. After a few fruitless debugging sessions I got hold of a PCH (eg20t) afflicted system. That machine does not have the CAN interface wired up, but it was possible to reproduce the issue with the HW loopback mode. As Alexander observed correctly, clearing the NewDat flag along with reading out the message buffer causes that issue on C_CAN, while D_CAN handles that correctly. Instead of restoring the original message buffer handling horror the following workaround solves the issue: transfer buffer to IF without clearing the NewDat handle the message clear NewDat bit That's similar to the original code but conditional for C_CAN. I really wonder why all user manuals (C_CAN, Intel PCH and some more) recommend to clear the NewDat bit right away. The knows it all Oracle operated by Gurgle does not unearth any useful information either. I simply cannot believe that we are the first to uncover that HW issue. Reported-and-tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Disable rx split as workaroundThomas Gleixner2-14/+55
The RX buffer split causes packet loss in the hardware: What happens is: RX Packet 1 --> message buffer 1 (newdat bit is not cleared) RX Packet 2 --> message buffer 2 (newdat bit is not cleared) RX Packet 3 --> message buffer 3 (newdat bit is not cleared) RX Packet 4 --> message buffer 4 (newdat bit is not cleared) RX Packet 5 --> message buffer 5 (newdat bit is not cleared) RX Packet 6 --> message buffer 6 (newdat bit is not cleared) RX Packet 7 --> message buffer 7 (newdat bit is not cleared) RX Packet 8 --> message buffer 8 (newdat bit is not cleared) Clear newdat bit in message buffer 1 Clear newdat bit in message buffer 2 Clear newdat bit in message buffer 3 Clear newdat bit in message buffer 4 Clear newdat bit in message buffer 5 Clear newdat bit in message buffer 6 Clear newdat bit in message buffer 7 Clear newdat bit in message buffer 8 Now if during that clearing of newdat bits, a new message comes in, the HW gets confused and drops it. It does not matter how many of them you clear. I put a delay between clear of buffer 1 and buffer 2 which was long enough that the message should have been queued either in buffer 1 or buffer 9. But it did not show up anywhere. The next message ended up in buffer 1. So the hardware lost a packet of course without telling it via one of the error handlers. That does not happen on all clear newdat bit events. I see one of 10k packets dropped in the scenario which allows us to reproduce. But the trace looks always the same. Not splitting the RX Buffer avoids the packet loss but can cause reordering. It's hard to trigger, but it CAN happen. With that mode we use the HW as it was probably designed for. We read from the buffer 1 upwards and clear the buffer as we get the message. That's how all microcontrollers use it. So I assume that the way we handle the buffers was never really tested. According to the public documentation it should just work :) Let the user decide which evil is the lesser one. [ Oliver Hartkopp: Provided a sane config option and help text and made me switch to favour potential and unlikely reordering over packet loss ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Get rid of pointless interruptsThomas Gleixner2-77/+48
The driver handles pointlessly TWO interrupts per packet. The reason is that it enables the status interrupt which fires for each rx and tx packet and it enables the per message object interrupts as well. The status interrupt merily acks or in case of D_CAN ignores the TX/RX state and then the message object interrupt fires. The message objects interrupts are only useful if all message objects have hardware filters activated. But we don't have that and its not simple to implement in that driver without rewriting it completely. So we can ditch the message object interrupts and handle the RX/TX right away from the status interrupt. Instead of TWO we handle ONE. Note: We must keep the TXIE/RXIE bits in the message buffers because the status interrupt alone is not reliable enough in corner cases. If we ever have the need for HW filtering, then this code needs a complete overhaul and we can think about it then. For now we prefer a lower interrupt load. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Avoid status register update for D_CANThomas Gleixner1-3/+6
On D_CAN the RXOK, TXOK and LEC bits are cleared/set on read of the status register. No need to update them. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Simplify buffer reenablingThomas Gleixner1-10/+6
Instead of writing to the message object we can simply clear the NewDat bit with the get method. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Always update error statsThomas Gleixner1-6/+7
If the allocation of the error skb fails, we still want to see the error statistics. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Fix berr reportingThomas Gleixner1-10/+6
Reading the LEC type with return (mode & ENABLED) && (status & LEC_MASK); is not guaranteed to return (status & LEC_MASK) if the enabled bit in mode is set. It's guaranteed to return 0 or !=0. Remove the inline function and call unconditionally into the berr_handling code and return early when the reporting is disabled. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Handle state change correctlyThomas Gleixner1-5/+20
If the allocation of an error skb fails, the state change handling returns w/o doing any work. That leaves the interface in a wreckaged state as the internal status is wrong. Split the interface handling and the skb handling. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Do not access skb after net_receive_skb()Thomas Gleixner1-5/+4
There is no guarantee that the skb is in the same state after calling net_receive_skb(). It might be freed or reused. Not really harmful as its a read access, except you turn on the proper debugging options which catch a use after free. The whole can subsystem is full of this. Copy and paste .... Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Make bus off interrupt disable logic workThomas Gleixner1-7/+4
The state change handler is called with device interrupts disabled already. So no point in disabling them again when we enter bus off state. But what's worse is that we reenable the interrupts at the end of NAPI poll unconditionally. So c_can_start() which is called from the restart timer can trigger interrupts which confuse the hell out of the half reinitialized driver/hw. Remove the pointless device interrupt disable in the BUS_OFF handler and prevent reenabling the device interrupts at the end of the poll routine when the current state is BUS_OFF. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can: Fix startup logicThomas Gleixner1-18/+17
c_can_start() enables interrupts way too early. The first enabling happens when setting the control mode in c_can_chip_config() and then again at the end of the function. But that happens before napi_enable() and that means that an interrupt which comes in will disable interrupts again and call napi_schedule, which ignores the request and the later napi_enable() is not making thinks work either. So the interface is up with all device interrupts disabled. Move the device interrupt after napi_enable() and add it to the other callsites of c_can_start() in c_can_set_mode() and c_can_power_up() Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24can: c_can_pci: Set the type of the IP coreThomas Gleixner1-0/+2
All type checks in c_can.c are != BOSCH_D_CAN so nobody noticed so far that the pci code does not update the type information. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-07Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAPUwe Kleine-König1-1/+1
If the renamed symbol is defined lib/iomap.c implements ioport_map and ioport_unmap and currently (nearly) all platforms define the port accessor functions outb/inb and friend unconditionally. So HAS_IOPORT_MAP is the better name for this. Consequently NO_IOPORT is renamed to NO_IOPORT_MAP. The motivation for this change is to reintroduce a symbol HAS_IOPORT that signals if outb/int et al are available. I will address that at least one merge window later though to keep surprises to a minimum and catch new introductions of (HAS|NO)_IOPORT. The changes in this commit were done using: $ git grep -l -E '(NO|HAS)_IOPORT' | xargs perl -p -i -e 's/\b((?:CONFIG_)?(?:NO|HAS)_IOPORT)\b/$1_MAP/' Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-01Merge tag 'linux-can-fixes-for-3.15-20140401' of ↵David S. Miller4-161/+265
git://gitorious.org/linux-can/linux-can linux-can-fixes-for-3.15-20140401 Marc Kleine-Budde says: ==================== this is a pull request of 16 patches for the 3.15 release cycle. Bjorn Van Tilt contributes a patch which fixes a memory leak in usb_8dev's usb_8dev_start_xmit()s error path. A patch by Robert Schwebel fixes a typo in the can documentation. The remaining patches all target the c_can driver. Two of them are by me; they add a missing netif_napi_del() and return value checking. Thomas Gleixner contributes 12 patches, which address several shortcomings in the driver like hardware initialisation, concurrency, message ordering and poor performance. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-01can: c_can: Avoid led toggling for every packet.Thomas Gleixner1-3/+4
There is no point to toggle the RX led for every packet. Especially if we have a full FIFO we want to avoid everything we can. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01can: c_can: Simplify TX interrupt cleanupThomas Gleixner1-20/+17
The function loads the message object from the hardware to get the payload length. The previous patch stores that information in an array, so we can avoid the hardware access. Remove the hardware access and move the led toggle outside of the spinlocked region. Toggle the led only once when at least one packet has been received. Binary size shrinks along with the code Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01can: c_can: Store dlc privateThomas Gleixner2-27/+29
We can avoid the HW access in TX cleanup path for retrieving the DLC of the sent package if we store the DLC in a private array. Ideally this should be handled in the can_echo_skb functions, but I leave that exercise to the CAN folks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01can: c_can: Reduce register accessThomas Gleixner1-34/+15
commit 4ce78a838c (can: c_can: Speed up rx_poll function) hyped a performance improvement by reducing the access to the interrupt pending register from a dual 16 bit to a single 16 bit access. Wow! Thereby it crippled the driver to cast the 16 msg objects in stone, which is completly braindead as contemporary hardware has up to 128 message objects. Supporting larger object buffers is a major surgery, but it'd be definitely worth it especially as the driver does not support HW message filtering .... The logic of the "FIFO" implementation is to split the FIFO in half. For the lower half we read the buffers and clear the interrupt pending bit, but keep the newdat bit set, so the HW will queue above those buffers. When we read out the last low buffer then we reenable all the low half buffers by clearing the newdat bit. The upper half buffers clear the newdat and the interrupt pending bit right away as we know that the lower half bits are clear and give us a headstart against the hardware. Now the implementation is: transfer_message_object() read_object_and_put_into_skb(); if (obj < END_OF_LOW_BUF) clear_intpending(obj) else if (obj > END_OF_LOW_BUF) clear_intpending_and_newdat(obj) else if (obj == END_OF_LOW_BUF) clear_newdat_of_all_low_objects() The hardware allows to avoid most of the mess simply because we can tell the transfer_message_object() function to clear bits right away. So we can be clever and do: if (obj <= END_OF_LOW_BUF) ctrl = TRANSFER_MSG | CLEAR_INTPND; else ctrl = TRANSFER_MSG | CLEAR_INTPND | CLEAR_NEWDAT; transfer_message_object(ctrl) read_object_and_put_into_skb(); if (obj == END_OF_LOW_BUF) clear_newdat_of_all_low_objects() So we save a complete control operation on all message objects except the one which is the end of the low buffer. That's a few micro seconds per object. I'm not adding a boasting profile to that, simply because it's self explaining. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [mkl: adjusted subject and commit message] Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01can: c_can: Make the code readableThomas Gleixner1-51/+56
If every other line contains line breaks, that's a clear sign for indentation level madness. Split out the inner loop and move the code to a separate function. gcc creates slightly worse code for that, but we'll fix that in the next step. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [mkl: adjusted subject] Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01can: c_can: Provide protection in the xmit pathThomas Gleixner2-1/+9
The network core does not serialize the access to the hardware. The xmit related code lets the following happen: CPU0 CPU1 interrupt() do_poll() c_can_do_tx() Fiddle with HW and xmit() internal data Fiddle with HW and internal data due the complete lack of serialization. Add proper locking. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01can: c_can: Remove EOB exitThomas Gleixner1-3/+0
The rx_poll code has the following gem: if (msg_ctrl_save & IF_MCONT_EOB) return num_rx_pkts; The EOB bit is the indicator for the hardware that this is the last configured FIFO object. But this object can contain valid data, if we manage to free up objects before the overrun case hits. Now if the code exits due to the EOB bit set, then this buffer is stale and the interrupt bit and NewDat bit of the buffer are still set. Results in a nice interrupt storm unless we come into an overrun situation where the MSGLST bit gets set. ksoftirqd/0-3 [000] ..s. 79.124101: c_can_poll: rx_poll: val: 00008001 pend 00008001 ksoftirqd/0-3 [000] ..s. 79.124176: c_can_poll: rx_poll: val: 00008000 pend 00008000 ksoftirqd/0-3 [000] ..s. 79.124187: c_can_poll: rx_poll: val: 00008002 pend 00008002 ksoftirqd/0-3 [000] ..s. 79.124256: c_can_poll: rx_poll: val: 00008000 pend 00008000 ksoftirqd/0-3 [000] ..s. 79.124267: c_can_poll: rx_poll: val: 00008000 pend 00008000 The amazing thing is that the check of the MSGLST (aka overrun bit) used to be after the check of the EOB bit. That was "fixed" in commit 5d0f801a2c(can: c_can: Fix RX message handling, handle lost message before EOB). But the author of this "fix" did not even understand that the EOB check is broken as well. Again a simple solution: Remove Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [mkl: adjusted subject and commit message] Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01can: c_can: Fix the lost message handlingThomas Gleixner1-16/+15
The lost message handling is broken in several ways. 1) Clearing the message lost flag is done by writing 0 to the message control register of the object. #define IF_MCONT_CLR_MSGLST (0 << 14) That clears the object buffer configuration in the worst case, which results in a loss of the EOB flag. That leaves the FIFO chain without a limit and causes a complete lockup of the HW 2) In case that the error skb allocation fails, the code happily claims that it handed down a packet. Just an accounting bug, but .... 3) The code adds a lot of pointless overhead to that error case, where we need to get stuff done as fast as possible to avoid more packet loss. - printk an annoying error message - reread the object buffer for nothing Fix is simple again: - Use the already known MSGCTRL content and only clear the MSGLST bit - Fix the buffer accounting by adding a proper return code - Remove the pointless operations Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01can: c_can: Fix buffer orderingThomas Gleixner1-2/+50
The buffer handling of c_can has been broken forever. That leads to message reordering: ksoftirqd/0-3 [000] ..s. 79.123776: c_can_poll: rx_poll: val: 00007fff ksoftirqd/0-3 [000] ..s. 79.124101: c_can_poll: rx_poll: val: 00008001 What happens is: CPU HW queue new packet into obj 16 (0-15 are busy) read obj 1-15 return because pending is 0 set pending obj 16 -> pending reg 8000 queue new packet into obj 1 set pending obj 1 -> pending reg 8001 So the current algorithmus reads the newest message first, which violates the ordering rules of CAN. Add proper handling of that situation by analyzing the contents of the pending register for gaps. This does NOT fix the message object corruption which can lead to interrupt storms. Thats addressed in the next patches. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [mkl: adjusted subject] Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01can: c_can: Make it SMP safeThomas Gleixner1-15/+21
The hardware has two message control interfaces, but the code only uses the first one. So on SMP the following can be observed: CPU0 CPU1 rx_poll() write IF1 xmit() write IF1 write IF1 That results in corrupted message object configurations. The TX/RX is not globally serialized it's only serialized on a core. Simple solution: Let RX use IF1 and TX use IF2 and all is good. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01can: c_can: Fix hardware raminit functionThomas Gleixner1-10/+37
The function is broken in several ways: - The function does not wait for the init to complete. That can take quite some microseconds. - No protection against being called for two chips at the same time. SMP is such a new thing, right? Clear the start and the init done bit unconditionally and wait for both bits to be clear. In the enable path set the init bit and wait for the init done bit. Add proper locking. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01can: c_can: Wait for CONTROL_INIT to be clearedThomas Gleixner1-3/+23
According to the documentation the CPU must wait for CONTROL_INIT to be cleared before writing to the baudrate registers. Signed-off-by: Benedikt Spranger <b.spranger@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01can: c_can: check return value to users of c_can_set_bittiming()Marc Kleine-Budde1-12/+22
This patch adds return value checking to all direct and indirect users of c_can_set_bittiming(). Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01can: c_can: free_c_can_dev(): add missing netif_napi_del()Marc Kleine-Budde1-0/+3
This patch adds the missing netif_napi_del() to the free_c_can_dev() function. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01can: usb_8dev: Fix memory leak in usb_8dev_start_xmitBjorn Van Tilt1-1/+1
Fixed a memory leak when an error occurred in the transmit function. In the error handling the urb wasn't freed before returning. There was also a call to the usb_unanchor_urb() function but the urb wasn't anchored. Signed-off-by: Bjorn Van Tilt <bjorn.vantilt@gmail.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-03-17can: mcp251x: Fix regulators operation without CONFIG_REGULATORAlexander Shiyan1-2/+2
If CONFIG_REGULATOR is not set, devm_regulator_get() returns NULL, so use IS_ERR_OR_NULL() macro for checks. Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-03-17can: populate netdev::dev_id for udev discriminationChristopher R. Baker10-0/+10
My objective is to be able to totally discriminate CAN ports on multi-port cards via udev so as to rename them to semantically interesting/unique names for my system (e.g., "ecuCAN" and "auxCAN" instead of "can0" and "can1"). The following patch assigns the dev_id field to match the channel number on all multi-channel devices. I can only test my two-port Peak PCI card, but it works as expected: ATTRS{dev_id} now expresses the port number and my udev rules now unambiguously pick out and rename my individual CAN ports. Signed-off-by: Christopher R. Baker <cbaker@rec.ri.cmu.edu> Tested-by: Oliver Hartkopp <socketcan@hartkopp.net> [PEAK PCAN-USB pro and EMS PCMCIA] Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-03-17can: Unify MTU settings for CAN interfacesOliver Hartkopp19-6/+30
CAN interfaces only support MTU values of 16 (CAN 2.0) and 72 (CAN FD). Setting the MTU to other values is pointless but it does not really hurt. With the introduction of the CAN FD support in drivers/net/can a new function to switch the MTU for CAN FD has been introduced. This patch makes use of this can_change_mtu() function to check for correct MTU settings also in legacy CAN (2.0) devices. Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-03-07can: add bittiming check at interface open for CAN FDOliver Hartkopp1-0/+8
Additionally to have the second (data) bitrate available the data bitrate has to be greater or equal to the arbitration bitrate in CAN FD. Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Acked-by: Stephane Grosjean <s.grosjean@peak-system.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-03-07can: allow to change the device mtu for CAN FD capable devicesOliver Hartkopp1-0/+39
The configuration for CAN FD depends on CAN_CTRLMODE_FD enabled in the driver specific ctrlmode_supported capabilities. The configuration can be done either with the 'fd { on | off }' option in the 'ip' tool from iproute2 or by setting the CAN netdevice MTU to CAN_MTU (16) or to CANFD_MTU (72). Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Acked-by: Stephane Grosjean <s.grosjean@peak-system.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>