diff mbox series

[net] sfc: fix TX channel offset when using legacy interrupts

Message ID 20220914103648.16902-1-ihuguet@redhat.com (mailing list archive)
State Accepted
Commit f232af4295653afa4ade3230462b3be15ad16419
Delegated to: Netdev Maintainers
Headers show
Series [net] sfc: fix TX channel offset when using legacy interrupts | expand

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Commit Message

Íñigo Huguet Sept. 14, 2022, 10:36 a.m. UTC
In legacy interrupt mode the tx_channel_offset was hardcoded to 1, but
that's not correct if efx_sepparate_tx_channels is false. In that case,
the offset is 0 because the tx queues are in the single existing channel
at index 0, together with the rx queue.

Without this fix, as soon as you try to send any traffic, it tries to
get the tx queues from an uninitialized channel getting these errors:
  WARNING: CPU: 1 PID: 0 at drivers/net/ethernet/sfc/tx.c:540 efx_hard_start_xmit+0x12e/0x170 [sfc]
  [...]
  RIP: 0010:efx_hard_start_xmit+0x12e/0x170 [sfc]
  [...]
  Call Trace:
   <IRQ>
   dev_hard_start_xmit+0xd7/0x230
   sch_direct_xmit+0x9f/0x360
   __dev_queue_xmit+0x890/0xa40
  [...]
  BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
  [...]
  RIP: 0010:efx_hard_start_xmit+0x153/0x170 [sfc]
  [...]
  Call Trace:
   <IRQ>
   dev_hard_start_xmit+0xd7/0x230
   sch_direct_xmit+0x9f/0x360
   __dev_queue_xmit+0x890/0xa40
  [...]

Fixes: c308dfd1b43e ("sfc: fix wrong tx channel offset with efx_separate_tx_channels")
Reported-by: Tianhao Zhao <tizhao@redhat.com>
Signed-off-by: Íñigo Huguet <ihuguet@redhat.com>
---
 drivers/net/ethernet/sfc/efx_channels.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Edward Cree Sept. 14, 2022, 5:47 p.m. UTC | #1
On 14/09/2022 11:36, Íñigo Huguet wrote:
> In legacy interrupt mode the tx_channel_offset was hardcoded to 1, but
> that's not correct if efx_sepparate_tx_channels is false. In that case,
> the offset is 0 because the tx queues are in the single existing channel
> at index 0, together with the rx queue.
> 
[...]
> 
> Fixes: c308dfd1b43e ("sfc: fix wrong tx channel offset with efx_separate_tx_channels")
> Reported-by: Tianhao Zhao <tizhao@redhat.com>
> Signed-off-by: Íñigo Huguet <ihuguet@redhat.com>

Acked-by: Edward Cree <ecree.xilinx@gmail.com>
patchwork-bot+netdevbpf@kernel.org Sept. 20, 2022, 1:20 a.m. UTC | #2
Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Wed, 14 Sep 2022 12:36:48 +0200 you wrote:
> In legacy interrupt mode the tx_channel_offset was hardcoded to 1, but
> that's not correct if efx_sepparate_tx_channels is false. In that case,
> the offset is 0 because the tx queues are in the single existing channel
> at index 0, together with the rx queue.
> 
> Without this fix, as soon as you try to send any traffic, it tries to
> get the tx queues from an uninitialized channel getting these errors:
>   WARNING: CPU: 1 PID: 0 at drivers/net/ethernet/sfc/tx.c:540 efx_hard_start_xmit+0x12e/0x170 [sfc]
>   [...]
>   RIP: 0010:efx_hard_start_xmit+0x12e/0x170 [sfc]
>   [...]
>   Call Trace:
>    <IRQ>
>    dev_hard_start_xmit+0xd7/0x230
>    sch_direct_xmit+0x9f/0x360
>    __dev_queue_xmit+0x890/0xa40
>   [...]
>   BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
>   [...]
>   RIP: 0010:efx_hard_start_xmit+0x153/0x170 [sfc]
>   [...]
>   Call Trace:
>    <IRQ>
>    dev_hard_start_xmit+0xd7/0x230
>    sch_direct_xmit+0x9f/0x360
>    __dev_queue_xmit+0x890/0xa40
>   [...]
> 
> [...]

Here is the summary with links:
  - [net] sfc: fix TX channel offset when using legacy interrupts
    https://git.kernel.org/netdev/net/c/f232af429565

You are awesome, thank you!
diff mbox series

Patch

diff --git a/drivers/net/ethernet/sfc/efx_channels.c b/drivers/net/ethernet/sfc/efx_channels.c
index 032b8c0bd788..5b4d661ab986 100644
--- a/drivers/net/ethernet/sfc/efx_channels.c
+++ b/drivers/net/ethernet/sfc/efx_channels.c
@@ -319,7 +319,7 @@  int efx_probe_interrupts(struct efx_nic *efx)
 		efx->n_channels = 1 + (efx_separate_tx_channels ? 1 : 0);
 		efx->n_rx_channels = 1;
 		efx->n_tx_channels = 1;
-		efx->tx_channel_offset = 1;
+		efx->tx_channel_offset = efx_separate_tx_channels ? 1 : 0;
 		efx->n_xdp_channels = 0;
 		efx->xdp_channel_offset = efx->n_channels;
 		efx->legacy_irq = efx->pci_dev->irq;