[PATCH 5.10.y] can: gs_usb: gs_usb_receive_bulk_callback(): resubmit URB on skb allocation failure

[Sasha Levin <sashal@kernel.org>]

From: Marc Kleine-Budde <mkl@pengutronix.de>

[ Upstream commit 68c5724ecd159992f76edb7b57dc508a44c8b7da ]

If the allocation of the SKB in gs_usb_receive_bulk_callback() fails, the
driver returns from the callback without resubmitting the URB in order to
receive further USB in URBs.

This results in a silent performance degradation which, if it occurs
repeatedly, results in starvation of USB in traffic.

Instead of returning immediately, try to resend the URB. If this also
fails, this is logged as an info message.

Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Fixes: 26949ac935e3 ("can: gs_usb: add CAN-FD support")
Link: https://patch.msgid.link/20260709-gs_usb-resubmit-urb-v1-1-4dd40030cc84@pengutronix.de
Cc: stable@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/can/usb/gs_usb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index ce5676845f284..87322bbd13253 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -332,7 +332,7 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
 	if (hf->echo_id == -1) { /* normal rx */
 		skb = alloc_can_skb(dev->netdev, &cf);
 		if (!skb)
-			return;
+			goto resubmit_urb;
 
 		cf->can_id = le32_to_cpu(hf->can_id);
 
-- 
2.53.0