[PATCH 6.18 298/396] can: gs_usb: gs_usb_receive_bulk_callback(): resubmit URB on skb allocation failure

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Marc Kleine-Budde <[email protected]>

commit 68c5724ecd159992f76edb7b57dc508a44c8b7da upstream.

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/[email protected]
Cc: [email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 drivers/net/can/usb/gs_usb.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -674,7 +674,7 @@ static void gs_usb_receive_bulk_callback
 		if (hf->flags & GS_CAN_FLAG_FD) {
 			skb = alloc_canfd_skb(netdev, &cfd);
 			if (!skb)
-				return;
+				goto resubmit_urb;
 
 			cfd->can_id = le32_to_cpu(hf->can_id);
 			cfd->len = data_length;
@@ -687,7 +687,7 @@ static void gs_usb_receive_bulk_callback
 		} else {
 			skb = alloc_can_skb(netdev, &cf);
 			if (!skb)
-				return;
+				goto resubmit_urb;
 
 			cf->can_id = le32_to_cpu(hf->can_id);
 			can_frame_set_cc_len(cf, hf->can_dlc, dev->can.ctrlmode);