+ Kedar
On 07/23/2015 11:13 PM, Andrea Scian wrote:
> Simply resetting the peripheral on RX FIFO overflow in not enough,
> because we also need to re-initialize the whole device.
> Also always enable RX FIFO overflow interrupt otherwise we may hang
> until another interrupt arrives (this happens if FIFO overrun and just
> read from CAN bus with candump)
>
> Signed-off-by: Andrea Scian <[email protected]>
> ---
>
> You can reproduce the problem with the following test-bed
> * connect a Zynq based board to a PC with a CAN bus adapter (e.g. PCAN USB)
> * start sending lots of CAN messages to Zynq system
> * configure and start xilinx CAN driver
> ** canconfig can0 bitrate 1000000
> ** canconfig can0 start
> * try to send/receive messages (cansend/candump)
> * if you send a CAN message you'll get the RX FIFO error and additional messages
> will not be received
> * if you try to get messages you simple don't receive them (no interrupt triggered)
> * with canconfig stop/start the hang goes away (if the others peers stop sending
> send lots of messages ;-) )
>
> I tested the patch over xilinx-2014.04 kernel, but the patch applies cleanly to
> mainline too.
>
> If someone has a better understanding of Xilinx CAN driver, please let me know if
> it's better to handle the error in a different manner.
>
> Maybe the bus off handler need the same threadment too.
>
> TIA,
>
> Andrea Scian
>
> ---
> drivers/net/can/xilinx_can.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
> index 5e8b560..c278177 100644
> --- a/drivers/net/can/xilinx_can.c
> +++ b/drivers/net/can/xilinx_can.c
> @@ -100,6 +100,7 @@ enum xcan_reg {
> #define XCAN_INTR_ALL (XCAN_IXR_TXOK_MASK | XCAN_IXR_BSOFF_MASK |\
> XCAN_IXR_WKUP_MASK | XCAN_IXR_SLP_MASK | \
> XCAN_IXR_RXNEMP_MASK | XCAN_IXR_ERROR_MASK | \
> + XCAN_IXR_RXOFLW_MASK | \
> XCAN_IXR_ARBLST_MASK | XCAN_IXR_RXOK_MASK)
>
> /* CAN register bit shift - XCAN_<REG>_<BIT>_SHIFT */
> @@ -526,6 +527,7 @@ static int xcan_rx(struct net_device *ndev)
> return 1;
> }
>
> +static void xcan_chip_stop(struct net_device *ndev);
> /**
> * xcan_err_interrupt - error frame Isr
> * @ndev: net_device pointer
> @@ -597,7 +599,8 @@ static void xcan_err_interrupt(struct net_device *ndev, u32 isr)
> if (isr & XCAN_IXR_RXOFLW_MASK) {
> stats->rx_over_errors++;
> stats->rx_errors++;
> - priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
> + xcan_chip_stop(ndev);
> + xcan_chip_start(ndev);
> if (skb) {
> cf->can_id |= CAN_ERR_CRTL;
> cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;
>
On 07/24/2015 06:15 AM, Michal Simek wrote:
> + Kedar
>
> On 07/23/2015 11:13 PM, Andrea Scian wrote:
>> Simply resetting the peripheral on RX FIFO overflow in not enough,
>> because we also need to re-initialize the whole device.
>> Also always enable RX FIFO overflow interrupt otherwise we may hang
>> until another interrupt arrives (this happens if FIFO overrun and just
>> read from CAN bus with candump)
>>
>> Signed-off-by: Andrea Scian <[email protected]>
Sorry, I missed the original patch. Can you repost it to:
[email protected]
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
Michal,
Kedar,
Any feedback regarding my patch?
Have you ever experienced such a problem?
Andrea SCIAN
*DAVE Embedded Systems*
via Talponedo 29/A 33080 Porcia (PN) - Italy
Telephone: +39.0434.921215
Telefax: +39.0434.1994030
web: http://www.dave.eu <http://www.dave.eu>
Il 24/07/2015 06:15, Michal Simek ha scritto:
> + Kedar
>
> On 07/23/2015 11:13 PM, Andrea Scian wrote:
>> Simply resetting the peripheral on RX FIFO overflow in not enough,
>> because we also need to re-initialize the whole device.
>> Also always enable RX FIFO overflow interrupt otherwise we may hang
>> until another interrupt arrives (this happens if FIFO overrun and just
>> read from CAN bus with candump)
>>
>> Signed-off-by: Andrea Scian <[email protected]>
>> ---
>>
>> You can reproduce the problem with the following test-bed
>> * connect a Zynq based board to a PC with a CAN bus adapter (e.g. PCAN USB)
>> * start sending lots of CAN messages to Zynq system
>> * configure and start xilinx CAN driver
>> ** canconfig can0 bitrate 1000000
>> ** canconfig can0 start
>> * try to send/receive messages (cansend/candump)
>> * if you send a CAN message you'll get the RX FIFO error and additional messages
>> will not be received
>> * if you try to get messages you simple don't receive them (no interrupt triggered)
>> * with canconfig stop/start the hang goes away (if the others peers stop sending
>> send lots of messages ;-) )
>>
>> I tested the patch over xilinx-2014.04 kernel, but the patch applies cleanly to
>> mainline too.
>>
>> If someone has a better understanding of Xilinx CAN driver, please let me know if
>> it's better to handle the error in a different manner.
>>
>> Maybe the bus off handler need the same threadment too.
>>
>> TIA,
>>
>> Andrea Scian
>>
>> ---
>> drivers/net/can/xilinx_can.c | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
>> index 5e8b560..c278177 100644
>> --- a/drivers/net/can/xilinx_can.c
>> +++ b/drivers/net/can/xilinx_can.c
>> @@ -100,6 +100,7 @@ enum xcan_reg {
>> #define XCAN_INTR_ALL (XCAN_IXR_TXOK_MASK | XCAN_IXR_BSOFF_MASK |\
>> XCAN_IXR_WKUP_MASK | XCAN_IXR_SLP_MASK | \
>> XCAN_IXR_RXNEMP_MASK | XCAN_IXR_ERROR_MASK | \
>> + XCAN_IXR_RXOFLW_MASK | \
>> XCAN_IXR_ARBLST_MASK | XCAN_IXR_RXOK_MASK)
>>
>> /* CAN register bit shift - XCAN_<REG>_<BIT>_SHIFT */
>> @@ -526,6 +527,7 @@ static int xcan_rx(struct net_device *ndev)
>> return 1;
>> }
>>
>> +static void xcan_chip_stop(struct net_device *ndev);
>> /**
>> * xcan_err_interrupt - error frame Isr
>> * @ndev: net_device pointer
>> @@ -597,7 +599,8 @@ static void xcan_err_interrupt(struct net_device *ndev, u32 isr)
>> if (isr & XCAN_IXR_RXOFLW_MASK) {
>> stats->rx_over_errors++;
>> stats->rx_errors++;
>> - priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
>> + xcan_chip_stop(ndev);
>> + xcan_chip_start(ndev);
>> if (skb) {
>> cf->can_id |= CAN_ERR_CRTL;
>> cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;
>>
>