Re: [PATCH] net/mlx5: stop waiting for PCI link if reset is required

Leon Romanovsky
2023-04-03T18:21:16Z

On Mon, Apr 03, 2023 at 09:56:56AM +0200, Niklas Schnelle wrote:
> after an error on the PCI link, the driver does not need to wait
> for the link to become functional again as a reset is required. Stop
> the wait loop in this case to accelerate the recovery flow.
>
> Co-developed-by: Alexander Schmidt <alexs@linux.ibm.com>
> Signed-off-by: Alexander Schmidt <alexs@linux.ibm.com>
> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
> ---
> drivers/net/ethernet/mellanox/mlx5/core/health.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/health.c b/drivers/net/ethernet/mellanox/mlx5/core/health.c
> index f9438d4e43ca..81ca44e0705a 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/health.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/health.c
> @@ -325,6 +325,8 @@ int mlx5_health_wait_pci_up(struct mlx5_core_dev *dev)
> while (sensor_pci_not_working(dev)) {

According to the comment in sensor_pci_not_working(), this loop is
supposed to wait till PCI will be ready again. Otherwise, already in
first iteration, we will bail out with pci_channel_offline() error.

Thanks

> if (time_after(jiffies, end))
> return -ETIMEDOUT;
> + if (pci_channel_offline(dev->pdev))
> + return -EIO;
> msleep(100);
> }
> return 0;
> @@ -332,10 +334,16 @@ int mlx5_health_wait_pci_up(struct mlx5_core_dev *dev)
>
> static int mlx5_health_try_recover(struct mlx5_core_dev *dev)
> {
> + int rc;
> +
> mlx5_core_warn(dev, "handling bad device here\n");
> mlx5_handle_bad_state(dev);
> - if (mlx5_health_wait_pci_up(dev)) {
> - mlx5_core_err(dev, "health recovery flow aborted, PCI reads still not working\n");
> + rc = mlx5_health_wait_pci_up(dev);
> + if (rc) {
> + if (rc == -ETIMEDOUT)
> + mlx5_core_err(dev, "health recovery flow aborted, PCI reads still not working\n");
> + else
> + mlx5_core_err(dev, "health recovery flow aborted, PCI channel offline\n");
> return -EIO;
> }
> mlx5_core_err(dev, "starting health recovery flow\n");
>
> base-commit: 7e364e56293bb98cae1b55fd835f5991c4e96e7d
> --
> 2.37.2
>