sfc: fix wrong tx channel offset with efx_separate_tx_channels

[ Upstream commit c308dfd1b43ef0d4c3e57b741bb3462eb7a7f4a2 ]

tx_channel_offset is calculated in efx_allocate_msix_channels, but it is
also calculated again in efx_set_channels because it was originally done
there, and when efx_allocate_msix_channels was introduced it was
forgotten to be removed from efx_set_channels.

Moreover, the old calculation is wrong when using
efx_separate_tx_channels because now we can have XDP channels after the
TX channels, so n_channels - n_tx_channels doesn't point to the first TX
channel.

Remove the old calculation from efx_set_channels, and add the
initialization of this variable if MSI or legacy interrupts are used,
next to the initialization of the rest of the related variables, where
it was missing.

Fixes: 3990a8fffbda ("sfc: allocate channels for XDP tx queues")
Reported-by: Tianhao Zhao <tizhao@redhat.com>
Signed-off-by: Íñigo Huguet <ihuguet@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/sfc/efx_channels.c b/drivers/net/ethernet/sfc/efx_channels.c
index eec0db76d888c9cb8c3429329dddb6a3a502ef25..8ab9358a1c3d70711857099291544c3f4753d1a9 100644 (file)
--- a/drivers/net/ethernet/sfc/efx_channels.c
+++ b/drivers/net/ethernet/sfc/efx_channels.c
@@ -309,6 +309,7 @@ int efx_probe_interrupts(struct efx_nic *efx)
                efx->n_channels = 1;
                efx->n_rx_channels = 1;
                efx->n_tx_channels = 1;
+               efx->tx_channel_offset = 0;
                efx->n_xdp_channels = 0;
                efx->xdp_channel_offset = efx->n_channels;
                rc = pci_enable_msi(efx->pci_dev);
@@ -329,6 +330,7 @@ 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->n_xdp_channels = 0;
                efx->xdp_channel_offset = efx->n_channels;
                efx->legacy_irq = efx->pci_dev->irq;
@@ -957,10 +959,6 @@ int efx_set_channels(struct efx_nic *efx)
        struct efx_channel *channel;
        int rc;
 
-       efx->tx_channel_offset =
-               efx_separate_tx_channels ?
-               efx->n_channels - efx->n_tx_channels : 0;
-
        if (efx->xdp_tx_queue_count) {
                EFX_WARN_ON_PARANOID(efx->xdp_tx_queues);