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* can: c_can_pci: enable PCI bus master only for MSIWolfgang Grandegger2014-04-24
| | | | | | | | | | | | | | | | 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>
* can: c_can: use proper type for 'instance'Wolfram Sang2014-04-24
| | | | | | | | | | 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>
* can: c_can: Speed up tx buffer invalidationThomas Gleixner2014-04-24
| | | | | | | | | | | 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>
* can: c_can: Remove tx lockingThomas Gleixner2014-04-24
| | | | | | | | | | | | | | | | | 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>
* can: c_can: Use proper u32 variables in c_can_write_msg_object()Thomas Gleixner2014-04-24
| | | | | | | | | | 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>
* can: c_can: Cleanup c_can_write_msg_object()Thomas Gleixner2014-04-24
| | | | | | | | | | | 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>
* can: c_can: Cleanup c_can_msg_obj_put/get()Thomas Gleixner2014-04-24
| | | | | | | | 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>
* can: c_can: Cleanup c_can_inval_msg_object()Thomas Gleixner2014-04-24
| | | | | | 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>
* can: c_can: Cleanup setup of receive buffersThomas Gleixner2014-04-24
| | | | | | 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>
* can: c_can: Cleanup c_can_read_msg_object()Thomas Gleixner2014-04-24
| | | | | | 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>
* can: c_can: Cleanup irq enable/disableThomas Gleixner2014-04-24
| | | | | | 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>
* can: c_can: Work around C_CAN RX wreckageThomas Gleixner2014-04-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* can: c_can: Disable rx split as workaroundThomas Gleixner2014-04-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* can: c_can: Get rid of pointless interruptsThomas Gleixner2014-04-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* can: c_can: Avoid status register update for D_CANThomas Gleixner2014-04-24
| | | | | | | | | 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>
* can: c_can: Simplify buffer reenablingThomas Gleixner2014-04-24
| | | | | | | | | 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>
* can: c_can: Always update error statsThomas Gleixner2014-04-24
| | | | | | | | | 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>
* can: c_can: Fix berr reportingThomas Gleixner2014-04-24
| | | | | | | | | | | | | | | | 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>
* can: c_can: Handle state change correctlyThomas Gleixner2014-04-24
| | | | | | | | | | | | 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>
* can: c_can: Do not access skb after net_receive_skb()Thomas Gleixner2014-04-24
| | | | | | | | | | | | | 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>
* can: c_can: Make bus off interrupt disable logic workThomas Gleixner2014-04-24
| | | | | | | | | | | | | | | | | | | 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>
* can: c_can: Fix startup logicThomas Gleixner2014-04-24
| | | | | | | | | | | | | | | | | | | 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>
* can: c_can_pci: Set the type of the IP coreThomas Gleixner2014-04-24
| | | | | | | | | 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>
* Merge tag 'linux-can-fixes-for-3.15-20140401' of ↵David S. Miller2014-04-01
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * can: c_can: Avoid led toggling for every packet.Thomas Gleixner2014-04-01
| | | | | | | | | | | | | | | | 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>
| * can: c_can: Simplify TX interrupt cleanupThomas Gleixner2014-04-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * can: c_can: Store dlc privateThomas Gleixner2014-04-01
| | | | | | | | | | | | | | | | | | | | | | 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>
| * can: c_can: Reduce register accessThomas Gleixner2014-04-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * can: c_can: Make the code readableThomas Gleixner2014-04-01
| | | | | | | | | | | | | | | | | | | | | | 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>
| * can: c_can: Provide protection in the xmit pathThomas Gleixner2014-04-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * can: c_can: Remove EOB exitThomas Gleixner2014-04-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * can: c_can: Fix the lost message handlingThomas Gleixner2014-04-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * can: c_can: Fix buffer orderingThomas Gleixner2014-04-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * can: c_can: Make it SMP safeThomas Gleixner2014-04-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * can: c_can: Fix hardware raminit functionThomas Gleixner2014-04-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * can: c_can: Wait for CONTROL_INIT to be clearedThomas Gleixner2014-04-01
| | | | | | | | | | | | | | | | | | 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>
| * can: c_can: check return value to users of c_can_set_bittiming()Marc Kleine-Budde2014-04-01
| | | | | | | | | | | | | | 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>
| * can: c_can: free_c_can_dev(): add missing netif_napi_del()Marc Kleine-Budde2014-04-01
| | | | | | | | | | | | This patch adds the missing netif_napi_del() to the free_c_can_dev() function. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* | can: Unify MTU settings for CAN interfacesOliver Hartkopp2014-03-17
|/ | | | | | | | | | | | | 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>
* can: c_can: Speed up rx_poll functionMarkus Pargmann2013-12-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch speeds up the rx_poll function by reducing the number of register reads. Replace the 32bit register read by a 16bit register read. Currently the 32bit register read is implemented by using 2 16bit reads. This is inefficient as we only use the lower 16bit in rx_poll. The for loop reads the pending interrupts in every iteration. This leads up to 16 reads of pending interrupts. The patch introduces a new outer loop to read the pending interrupts as long as 'quota' is above 0. This reduces the total number of reads. The third change is to replace the for-loop by a ffs loop. Tested on AM335x. I removed all 'static' and 'inline' from c_can.c to see the timings for all functions. I used the function tracer with trace_stats. 125kbit: Function Hit Time Avg s^2 -------- --- ---- --- --- c_can_do_rx_poll 63960 10168178 us 158.977 us 1493056 us With patch: c_can_do_rx_poll 63941 3764057 us 58.867 us 776162.2 us 1Mbit: Function Hit Time Avg s^2 -------- --- ---- --- --- c_can_do_rx_poll 69489 30049498 us 432.435 us 9271851 us With patch: c_can_do_rx_poll 207109 24322185 us 117.436 us 171469047 us Signed-off-by: Markus Pargmann <mpa@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: fix calculation of transmitted bytes on tx completeHolger Bechtold2013-11-25
| | | | | | | | | | | | | | | The number of bytes transmitted was not updated correctly, if several CAN messages (with different length) were transmitted in one 'bunch'. Thus programs like 'ifconfig' showed wrong transmit byte counts. Reason was, that the message object whose DLC is to be read was not necessarily the active one at the time when priv->read_reg(priv, C_CAN_IFACE(MSGCTRL_REG, 0)) & IF_MCONT_DLC_MASK; was executed. Signed-off-by: Holger Bechtold <Holger.Bechtold@gmx.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: don't call pm_runtime_get_sync() from interrupt contextMarc Kleine-Budde2013-11-25
| | | | | | | | | | | | | | | The c_can driver contians a callpath (c_can_poll -> c_can_state_change -> c_can_get_berr_counter) which may call pm_runtime_get_sync() from the IRQ handler, which is not allowed and results in "BUG: scheduling while atomic". This problem is fixed by introducing __c_can_get_berr_counter, which will not call pm_runtime_get_sync(). Reported-by: Andrew Glen <AGlen@bepmarine.com> Tested-by: Andrew Glen <AGlen@bepmarine.com> Signed-off-by: Andrew Glen <AGlen@bepmarine.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2013-11-04
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: drivers/net/ethernet/emulex/benet/be.h drivers/net/netconsole.c net/bridge/br_private.h Three mostly trivial conflicts. The net/bridge/br_private.h conflict was a function signature (argument addition) change overlapping with the extern removals from Joe Perches. In drivers/net/netconsole.c we had one change adjusting a printk message whilst another changed "printk(KERN_INFO" into "pr_info(". Lastly, the emulex change was a new inline function addition overlapping with Joe Perches's extern removals. Signed-off-by: David S. Miller <davem@davemloft.net>
| * can: c_can: Fix RX message handling, handle lost message before EOBMarkus Pargmann2013-10-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | If we handle end of block messages with higher priority than a lost message, we can run into an endless interrupt loop. This is reproducable with a am335x processor and "cansequence -r" at 1Mbit. As soon as we loose a packet we can't escape from an interrupt loop. This patch fixes the problem by handling lost packets before EOB packets. Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Markus Pargmann <mpa@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* | net: can: c_can_platform: Remove redundant of_match_ptrSachin Kamat2013-10-01
| | | | | | | | | | | | | | | | | | | | The data structure of_match_ptr() protects is always compiled in. Hence of_match_ptr() is not needed. Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Cc: Marc Kleine-Budde <mkl@pengutronix.de> Cc: linux-can@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
* | can: c_can: remove unnecessary pci_set_drvdata()Jingoo Han2013-09-21
|/ | | | | | | | | The driver core clears the driver data to NULL after device_release or on probe failure. Thus, it is not needed to manually clear the device driver data to NULL. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: fix error checking of priv->instance in probe()Chen Gang2013-08-22
| | | | | | | | | | | | This patch adds a type cast from 'unsigned int' to 'int'. 'priv->instance' may less than zero, so need a type cast, the related warnings (allmodconfig, "EXTRA_CFLAGS=-W"): drivers/net/can/c_can/c_can_platform.c:198:3: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] Signed-off-by: Chen Gang <gang.chen@asianux.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* drivers/net/can/c_can: don't use devm_pinctrl_get_select_default() in probeWolfram Sang2013-07-11
| | | | | | | | | | Since commit ab78029 (drivers/pinctrl: grab default handles from device core), we can rely on device core for setting the default pins. Compile tested only. Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13) Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: can: Convert to use devm_ioremap_resourceTushar Behera2013-06-12
| | | | | | | | | | | | | | Commit 75096579c3ac ("lib: devres: Introduce devm_ioremap_resource()") introduced devm_ioremap_resource() and deprecated the use of devm_request_and_ioremap(). Signed-off-by: Tushar Behera <tushar.behera@linaro.org> CC: netdev@vger.kernel.org CC: linux-can@vger.kernel.org CC: Marc Kleine-Budde <mkl@pengutronix.de> CC: Wolfgang Grandegger <wg@grandegger.com> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: can: c_can: remove unnecessary platform_set_drvdata()Jingoo Han2013-05-16
| | | | | | | | | | The driver core clears the driver data to NULL after device_release or on probe failure, since commit 0998d0631001288a5974afc0b2a5f568bcdecb4d (device-core: Ensure drvdata = NULL when no driver is bound). Thus, it is not needed to manually clear the device driver data to NULL. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-24 01:44:25 -0500