Message ID | 20171019190736.2770-1-jean-philippe.brucker@arm.com |
---|---|
State | Awaiting Upstream, archived |
Delegated to: | David Miller |
Headers | show |
Series | igb: Fix TX map failure path | expand |
On Thu, Oct 19, 2017 at 12:07 PM, Jean-Philippe Brucker <jean-philippe.brucker@arm.com> wrote: > 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 <jean-philippe.brucker@arm.com> > --- > drivers/net/ethernet/intel/igb/igb_main.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c > index fd4a46b03cc8..ea69af267d63 100644 > --- a/drivers/net/ethernet/intel/igb/igb_main.c > +++ b/drivers/net/ethernet/intel/igb/igb_main.c > @@ -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 <alexander.h.duyck@intel.com>
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index fd4a46b03cc8..ea69af267d63 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -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]; }
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 <jean-philippe.brucker@arm.com> --- drivers/net/ethernet/intel/igb/igb_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)