This is a note to let you know that I've just added the patch titled
sfc: fix XDP queues mode with legacy IRQ
to the 6.3-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-xdp-queues-mode-with-legacy-irq.patch
and it can be found in the queue-6.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 543b2dee145d5fb9e49647b62bfebea178a443cf
Author: Íñigo Huguet <ihuguet@xxxxxxxxxx>
Date: Tue Jun 13 15:38:54 2023 +0200
sfc: fix XDP queues mode with legacy IRQ
[ Upstream commit e84a1e1e683f3558e30f437d7c99df35afb8b52c ]
In systems without MSI-X capabilities, xdp_txq_queues_mode is calculated
in efx_allocate_msix_channels, but when enabling MSI-X fails, it was not
changed to a proper default value. This was leading to the driver
thinking that it has dedicated XDP queues, when it didn't.
Fix it by setting xdp_txq_queues_mode to the correct value if the driver
fallbacks to MSI or legacy IRQ mode. The correct value is
EFX_XDP_TX_QUEUES_BORROWED because there are no XDP dedicated queues.
The issue can be easily visible if the kernel is started with pci=nomsi,
then a call trace is shown. It is not shown only with sfc's modparam
interrupt_mode=2. Call trace example:
WARNING: CPU: 2 PID: 663 at drivers/net/ethernet/sfc/efx_channels.c:828 efx_set_xdp_channels+0x124/0x260 [sfc]
[...skip...]
Call Trace:
<TASK>
efx_set_channels+0x5c/0xc0 [sfc]
efx_probe_nic+0x9b/0x15a [sfc]
efx_probe_all+0x10/0x1a2 [sfc]
efx_pci_probe_main+0x12/0x156 [sfc]
efx_pci_probe_post_io+0x18/0x103 [sfc]
efx_pci_probe.cold+0x154/0x257 [sfc]
local_pci_probe+0x42/0x80
Fixes: 6215b608a8c4 ("sfc: last resort fallback for lack of xdp tx queues")
Reported-by: Yanghang Liu <yanghliu@xxxxxxxxxx>
Signed-off-by: Íñigo Huguet <ihuguet@xxxxxxxxxx>
Acked-by: Martin Habets <habetsm.xilinx@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
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 fcea3ea809d77..41b33a75333cd 100644
--- a/drivers/net/ethernet/sfc/efx_channels.c
+++ b/drivers/net/ethernet/sfc/efx_channels.c
@@ -301,6 +301,7 @@ int efx_probe_interrupts(struct efx_nic *efx)
efx->tx_channel_offset = 0;
efx->n_xdp_channels = 0;
efx->xdp_channel_offset = efx->n_channels;
+ efx->xdp_txq_queues_mode = EFX_XDP_TX_QUEUES_BORROWED;
rc = pci_enable_msi(efx->pci_dev);
if (rc == 0) {
efx_get_channel(efx, 0)->irq = efx->pci_dev->irq;
@@ -322,6 +323,7 @@ int efx_probe_interrupts(struct efx_nic *efx)
efx->tx_channel_offset = efx_separate_tx_channels ? 1 : 0;
efx->n_xdp_channels = 0;
efx->xdp_channel_offset = efx->n_channels;
+ efx->xdp_txq_queues_mode = EFX_XDP_TX_QUEUES_BORROWED;
efx->legacy_irq = efx->pci_dev->irq;
}
diff --git a/drivers/net/ethernet/sfc/siena/efx_channels.c b/drivers/net/ethernet/sfc/siena/efx_channels.c
index 06ed74994e366..1776f7f8a7a90 100644
--- a/drivers/net/ethernet/sfc/siena/efx_channels.c
+++ b/drivers/net/ethernet/sfc/siena/efx_channels.c
@@ -302,6 +302,7 @@ int efx_siena_probe_interrupts(struct efx_nic *efx)
efx->tx_channel_offset = 0;
efx->n_xdp_channels = 0;
efx->xdp_channel_offset = efx->n_channels;
+ efx->xdp_txq_queues_mode = EFX_XDP_TX_QUEUES_BORROWED;
rc = pci_enable_msi(efx->pci_dev);
if (rc == 0) {
efx_get_channel(efx, 0)->irq = efx->pci_dev->irq;
@@ -323,6 +324,7 @@ int efx_siena_probe_interrupts(struct efx_nic *efx)
efx->tx_channel_offset = efx_siena_separate_tx_channels ? 1 : 0;
efx->n_xdp_channels = 0;
efx->xdp_channel_offset = efx->n_channels;
+ efx->xdp_txq_queues_mode = EFX_XDP_TX_QUEUES_BORROWED;
efx->legacy_irq = efx->pci_dev->irq;
}
