target/linux/lantiq/patches-5.10/0718-v6.0-net-lantiq_xrx200-fix-lock-under-memory-pressure.patch

   1 From c4b6e9341f930e4dd089231c0414758f5f1f9dbd Mon Sep 17 00:00:00 2001
   2 From: Aleksander Jan Bajkowski <olek2@wp.pl>
   3 Date: Wed, 24 Aug 2022 23:54:07 +0200
   4 Subject: [PATCH] net: lantiq_xrx200: fix lock under memory pressure
   5
   6 When the xrx200_hw_receive() function returns -ENOMEM, the NAPI poll
   7 function immediately returns an error.
   8 This is incorrect for two reasons:
   9 * the function terminates without enabling interrupts or scheduling NAPI,
  10 * the error code (-ENOMEM) is returned instead of the number of received
  11 packets.
  12
  13 After the first memory allocation failure occurs, packet reception is
  14 locked due to disabled interrupts from DMA..
  15
  16 Fixes: fe1a56420cf2 ("net: lantiq: Add Lantiq / Intel VRX200 Ethernet driver")
  17 Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
  18 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  19 ---
  20  drivers/net/ethernet/lantiq_xrx200.c | 2 +-
  21  1 file changed, 1 insertion(+), 1 deletion(-)
  22
  23 --- a/drivers/net/ethernet/lantiq_xrx200.c
  24 +++ b/drivers/net/ethernet/lantiq_xrx200.c
  25 @@ -294,7 +294,7 @@ static int xrx200_poll_rx(struct napi_st
  26                         if (ret == XRX200_DMA_PACKET_IN_PROGRESS)
  27                                 continue;
  28                         if (ret != XRX200_DMA_PACKET_COMPLETE)
  29 -                               return ret;
  30 +                               break;
  31                         rx++;
  32                 } else {
  33                         break;