[lkml]   [2019]   [Dec]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH 5.3 058/135] can: rx-offload: can_rx_offload_irq_offload_fifo(): continue on error
From: Marc Kleine-Budde <>

[ Upstream commit 1f7f504dcd9d1262437bdcf4fa071e41dec1af03 ]

In case of a resource shortage, i.e. the rx_offload queue will overflow
or a skb fails to be allocated (due to OOM),
can_rx_offload_offload_one() will call mailbox_read() to discard the
mailbox and return an ERR_PTR.

If the hardware FIFO is empty can_rx_offload_offload_one() will return

In case a CAN frame was read from the hardware,
can_rx_offload_offload_one() returns the skb containing it.

Without this patch can_rx_offload_irq_offload_fifo() bails out if no skb
returned, regardless of the reason.

Similar to can_rx_offload_irq_offload_timestamp() in case of a resource
shortage the whole FIFO should be discarded, to avoid an IRQ storm and
give the system some time to recover. However if the FIFO is empty the
loop can be left.

With this patch the loop is left in case of empty FIFO, but not on

Signed-off-by: Marc Kleine-Budde <>
Signed-off-by: Sasha Levin <>
drivers/net/can/rx-offload.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/can/rx-offload.c b/drivers/net/can/rx-offload.c
index 2ea8676579a9c..84cae167e42f6 100644
--- a/drivers/net/can/rx-offload.c
+++ b/drivers/net/can/rx-offload.c
@@ -248,7 +248,9 @@ int can_rx_offload_irq_offload_fifo(struct can_rx_offload *offload)

while (1) {
skb = can_rx_offload_offload_one(offload, 0);
- if (IS_ERR_OR_NULL(skb))
+ if (IS_ERR(skb))
+ continue;
+ if (!skb)

skb_queue_tail(&offload->skb_queue, skb);

 \ /
  Last update: 2019-12-03 23:41    [W:0.436 / U:0.800 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site