When there's an error attempting to store the BER counter, don't abort but continue shutting down the chip as required. After disabling communications, also stop the TX queue with a call to netif_stop_queue. When the interface restarts, mcp251xfd_set_mode will call netif_wake_queue and resume. This fixes a hangup in either send() or poll() from userspace. To reproduce: I ran "cansequence can0 -p" to flood the system with packets. While running that, I shorted the CAN signals, causing a bus error. Usually communications would resume after the CAN bus restarted, but sometimes the system got stuck and refused to send any more packets. The sending process would be in either poll() or send(), waiting for the queue to resume. To "unstuck" the process from send() it was sufficient to send any packet on the can interface from another process. To get it out of the poll() hang, only bringing the can interface down (and up) would work. After adding the netif_stop_queue call, I was unable to reproduce the problem. Signed-off-by: Mike Looijmans <mike.looijmans@xxxxxxxx> --- drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c index 68df6d4641b5..854e0644764c 100644 --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c @@ -1084,10 +1084,11 @@ static int mcp251xfd_handle_cerrif(struct mcp251xfd_priv *priv) */ err = __mcp251xfd_get_berr_counter(priv->ndev, &priv->bec); if (err) - return err; + netdev_err(priv->ndev, "Failed to store BER counter\n"); mcp251xfd_chip_stop(priv, CAN_STATE_BUS_OFF); can_bus_off(priv->ndev); + netif_stop_queue(priv->ndev); } if (!skb) -- 2.17.1 Met vriendelijke groet / kind regards, Mike Looijmans System Expert TOPIC Embedded Products B.V. Materiaalweg 4, 5681 RJ Best The Netherlands T: +31 (0) 499 33 69 69 E: mike.looijmans@xxxxxxxxxxxxxxxxx W: www.topic.nl Please consider the environment before printing this e-mail
