[PATCH 4.19 032/321] can: rx-offload: can_rx_offload_irq_offload_timestamp(): continue on error

Greg Kroah-Hartman
2019-12-03T22:46:37Z

From: Jeroen Hofstee <jhofstee@victronenergy.com>

[ Upstream commit c2a9f74c9d18acfdcabd3361adc7eac82c537a66 ]

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.

However can_rx_offload_irq_offload_timestamp() bails out in the error
case. In case of a resource shortage all mailboxes should be discarded,
to avoid an IRQ storm and give the system some time to recover.

Since can_rx_offload_irq_offload_timestamp() is typically called from a
while loop, all message will eventually be discarded. So let's continue
on error instead to discard them directly.

Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/can/rx-offload.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/can/rx-offload.c b/drivers/net/can/rx-offload.c
index 1b3ce70c55bc7..0dded7a1067bb 100644
--- a/drivers/net/can/rx-offload.c
+++ b/drivers/net/can/rx-offload.c
@@ -225,7 +225,7 @@ int can_rx_offload_irq_offload_timestamp(struct can_rx_offload *offload, u64 pen

skb = can_rx_offload_offload_one(offload, i);
if (IS_ERR_OR_NULL(skb))
- break;
+ continue;

__skb_queue_add_sort(&skb_queue, skb, can_rx_offload_compare);
}
--
2.20.1