From: =?UTF-8?q?=C3=8D=C3=B1igo=20Huguet?= <ihuguet@redhat.com>
Date: Wed, 1 Jun 2022 08:36:03 +0200
Subject: sfc/siena: fix wrong tx channel offset with efx_separate_tx_channels
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Patch-mainline: v5.19-rc1
Git-commit: 25bde571b4a83a73bb37beacb833bbd9c38b43c6
References: jsc#PED-1565

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.

This has been already done for sfc, do it also for sfc_siena.

Fixes: 3990a8fffbda ("sfc: allocate channels for XDP tx queues")
Reported-by: Tianhao Zhao <tizhao@redhat.com>
Signed-off-by: Íñigo Huguet <ihuguet@redhat.com>
Acked-by: Martin Habets <habetsm.xilinx@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/sfc/siena/efx_channels.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

--- a/drivers/net/ethernet/sfc/siena/efx_channels.c
+++ b/drivers/net/ethernet/sfc/siena/efx_channels.c
@@ -304,6 +304,7 @@ int efx_siena_probe_interrupts(struct ef
 		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);
@@ -324,6 +325,7 @@ int efx_siena_probe_interrupts(struct ef
 		efx->n_channels = 1 + (efx_siena_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;
@@ -963,10 +965,6 @@ int efx_siena_set_channels(struct efx_ni
 	struct efx_channel *channel;
 	int rc;
 
-	efx->tx_channel_offset =
-		efx_siena_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);