When the driver cannot map a TX buffer, instead of rolling back
gracefully and retrying later, we currently get a panic:
[ 159.885994] igb 0000:00:00.0: TX DMA map failed
[ 159.886588] Unable to handle kernel paging request at virtual address ffff00000a08c7a8
...
[ 159.897031] PC is at igb_xmit_frame_ring+0x9c8/0xcb8
Fix the erroneous test that leads to this situation.
Signed-off-by: Jean-Philippe Brucker <redacted>
---
drivers/net/ethernet/intel/igb/igb_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
From: Alexander Duyck <hidden> Date: 2017-10-19 19:58:31
On Thu, Oct 19, 2017 at 12:07 PM, Jean-Philippe Brucker
[off-list ref] wrote:
quoted hunk
When the driver cannot map a TX buffer, instead of rolling back
gracefully and retrying later, we currently get a panic:
[ 159.885994] igb 0000:00:00.0: TX DMA map failed
[ 159.886588] Unable to handle kernel paging request at virtual address ffff00000a08c7a8
...
[ 159.897031] PC is at igb_xmit_frame_ring+0x9c8/0xcb8
Fix the erroneous test that leads to this situation.
Signed-off-by: Jean-Philippe Brucker <redacted>
---
drivers/net/ethernet/intel/igb/igb_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
@@ -5326,7 +5326,7 @@ static int igb_tx_map(struct igb_ring *tx_ring,DMA_TO_DEVICE);dma_unmap_len_set(tx_buffer,len,0);-if(i--)+if(i--==0)i+=tx_ring->count;tx_buffer=&tx_ring->tx_buffer_info[i];}
The fix looks fine to me, though I will probably want to go back and
update the code to simplify this since I realize part of the issue is
that there is a bunch of unneeded complexity I introduced here. It
looks like we have the same problem in ixgbe that needs to be
addressed as well.
Fixes: 7cc6fd4c60f2 ("igb: Don't bother clearing Tx buffer_info in
igb_clean_tx_ring")
Acked-by: Alexander Duyck <redacted>