[PATCH net v2 0/2] sfc: fix some efx_separate_tx_channels errors

[PATCH net v2 0/2] sfc: fix some efx_separate_tx_channels errors

[Íñigo Huguet]

Trying to load sfc driver with modparam efx_separate_tx_channels=1
resulted in errors during initialization and not being able to use the
NIC. This patches fix a few bugs and make it work again.

v2:
* added Martin's patch instead of a previous mine. Mine one solved some
of the initialization errors, but Martin's solves them also in all 
possible cases.
* removed whitespaces cleanup, as requested by Jakub

Martin Habets (1):
  sfc: fix considering that all channels have TX queues

Íñigo Huguet (1):
  sfc: fix wrong tx channel offset with efx_separate_tx_channels

 drivers/net/ethernet/sfc/efx_channels.c | 6 ++----
 drivers/net/ethernet/sfc/net_driver.h   | 2 +-
 2 files changed, 3 insertions(+), 5 deletions(-)

-- 
2.34.1

[PATCH net v2 1/2] sfc: fix considering that all channels have TX queues

[Íñigo Huguet]

From: Martin Habets <habetsm.xilinx@gmail.com>

Normally, all channels have RX and TX queues, but this is not true if
modparam efx_separate_tx_channels=1 is used. In that cases, some
channels only have RX queues and others only TX queues (or more
preciselly, they have them allocated, but not initialized).

Fix efx_channel_has_tx_queues to return the correct value for this case
too.

Messages shown at probe time before the fix:
 sfc 0000:03:00.0 ens6f0np0: MC command 0x82 inlen 544 failed rc=-22 (raw=0) arg=0
 ------------[ cut here ]------------
 netdevice: ens6f0np0: failed to initialise TXQ -1
 WARNING: CPU: 1 PID: 626 at drivers/net/ethernet/sfc/ef10.c:2393 efx_ef10_tx_init+0x201/0x300 [sfc]
 [...] stripped
 RIP: 0010:efx_ef10_tx_init+0x201/0x300 [sfc]
 [...] stripped
 Call Trace:
  efx_init_tx_queue+0xaa/0xf0 [sfc]
  efx_start_channels+0x49/0x120 [sfc]
  efx_start_all+0x1f8/0x430 [sfc]
  efx_net_open+0x5a/0xe0 [sfc]
  __dev_open+0xd0/0x190
  __dev_change_flags+0x1b3/0x220
  dev_change_flags+0x21/0x60
 [...] stripped

Messages shown at remove time before the fix:
 sfc 0000:03:00.0 ens6f0np0: failed to flush 10 queues
 sfc 0000:03:00.0 ens6f0np0: failed to flush queues

Fixes: 8700aff08984 ("sfc: fix channel allocation with brute force")
Reported-by: Tianhao Zhao <tizhao@redhat.com>
Signed-off-by: Martin Habets <habetsm.xilinx@gmail.com>
Tested-by: Íñigo Huguet <ihuguet@redhat.com>
---
 drivers/net/ethernet/sfc/net_driver.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index c75dc75e2857..d7255d54707c 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -1535,7 +1535,7 @@ static inline bool efx_channel_is_xdp_tx(struct efx_channel *channel)
 
 static inline bool efx_channel_has_tx_queues(struct efx_channel *channel)
 {
-	return true;
+	return channel && channel->channel >= channel->efx->tx_channel_offset;
 }
 
 static inline unsigned int efx_channel_num_tx_queues(struct efx_channel *channel)
-- 
2.34.1

[PATCH net v2 2/2] sfc: fix wrong tx channel offset with efx_separate_tx_channels

[Íñigo Huguet]

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>
---
 drivers/net/ethernet/sfc/efx_channels.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/sfc/efx_channels.c b/drivers/net/ethernet/sfc/efx_channels.c
index 40df910aa140..b9cf873e1e42 100644
--- a/drivers/net/ethernet/sfc/efx_channels.c
+++ b/drivers/net/ethernet/sfc/efx_channels.c
@@ -324,6 +324,7 @@ 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);
@@ -344,6 +345,7 @@ 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;
@@ -979,10 +981,6 @@ 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);
 
-- 
2.34.1

Re: [PATCH net v2 0/2] sfc: fix some efx_separate_tx_channels errors

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (master)
by David S. Miller <davem@davemloft.net>:

On Fri, 27 May 2022 10:05:27 +0200 you wrote:
> Trying to load sfc driver with modparam efx_separate_tx_channels=1
> resulted in errors during initialization and not being able to use the
> NIC. This patches fix a few bugs and make it work again.
> 
> v2:
> * added Martin's patch instead of a previous mine. Mine one solved some
> of the initialization errors, but Martin's solves them also in all
> possible cases.
> * removed whitespaces cleanup, as requested by Jakub
> 
> [...]

Here is the summary with links:
  - [net,v2,1/2] sfc: fix considering that all channels have TX queues
    https://git.kernel.org/netdev/net/c/2e102b53f8a7
  - [net,v2,2/2] sfc: fix wrong tx channel offset with efx_separate_tx_channels
    https://git.kernel.org/netdev/net/c/c308dfd1b43e

You are awesome, thank you!
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