This is a note to let you know that I've just added the patch titled
sfc: fix TX channel offset when using legacy interrupts
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
sfc-fix-tx-channel-offset-when-using-legacy-interrup.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1f0be45d8d7d72fa772fc2dbfc958bb3061771ba
Author: Íñigo Huguet <ihuguet@xxxxxxxxxx>
Date: Wed Sep 14 12:36:48 2022 +0200
sfc: fix TX channel offset when using legacy interrupts
[ Upstream commit f232af4295653afa4ade3230462b3be15ad16419 ]
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@xxxxxxxxxx>
Signed-off-by: Íñigo Huguet <ihuguet@xxxxxxxxxx>
Acked-by: Edward Cree <ecree.xilinx@xxxxxxxxx>
Link: https://lore.kernel.org/r/20220914103648.16902-1-ihuguet@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/sfc/efx_channels.c b/drivers/net/ethernet/sfc/efx_channels.c
index d0f1b2dc7dff..c49168ba7a4d 100644
--- a/drivers/net/ethernet/sfc/efx_channels.c
+++ b/drivers/net/ethernet/sfc/efx_channels.c
@@ -308,7 +308,7 @@ 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;
