Re: [PATCH mlx5-next 01/10] net/mlx5: Rework handling of port module events

Saeed Mahameed
2018-12-10T19:07:36Z

On Mon, Dec 10, 2018 at 8:09 AM Jason Gunthorpe <jgg@mellanox.com> wrote:
>
> On Sun, Dec 09, 2018 at 07:04:33PM -0800, Saeed Mahameed wrote:
> > From: Mikhael Goikhman <migo@mellanox.com>
> >
> > Add explicit HW defined error values. For simplicity, keep counters for all
> > statuses starting from 0, although currently status=0 is not used.
> >
> > Additionally, when HW signals an unexpected cable status, it is reported
> > now rather than ignored. And status counter is now updated on errors.
> >
> > Signed-off-by: Mikhael Goikhman <migo@mellanox.com>
> > Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
> > .../ethernet/mellanox/mlx5/core/en_stats.c | 8 +-
> > .../net/ethernet/mellanox/mlx5/core/events.c | 83 ++++++++++++-------
> > .../ethernet/mellanox/mlx5/core/lib/mlx5.h | 19 ++---
> > 3 files changed, 65 insertions(+), 45 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
> > index 748d23806391..881c54c12e19 100644
> > +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
> > @@ -1087,13 +1087,13 @@ static void mlx5e_grp_per_prio_update_stats(struct mlx5e_priv *priv)
> > }
> >
> > static const struct counter_desc mlx5e_pme_status_desc[] = {
> > - { "module_unplug", 8 },
> > + { "module_unplug", sizeof(u64) * MLX5_MODULE_STATUS_UNPLUGGED },
> > };
> >
> > static const struct counter_desc mlx5e_pme_error_desc[] = {
> > - { "module_bus_stuck", 16 }, /* bus stuck (I2C or data shorted) */
> > - { "module_high_temp", 48 }, /* high temperature */
> > - { "module_bad_shorted", 56 }, /* bad or shorted cable/module */
> > + { "module_bus_stuck", sizeof(u64) * MLX5_MODULE_EVENT_ERROR_BUS_STUCK },
> > + { "module_high_temp", sizeof(u64) * MLX5_MODULE_EVENT_ERROR_HIGH_TEMPERATURE },
> > + { "module_bad_shorted", sizeof(u64) * MLX5_MODULE_EVENT_ERROR_BAD_CABLE },
> > };
> >
> > #define NUM_PME_STATUS_STATS ARRAY_SIZE(mlx5e_pme_status_desc)
> > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/events.c b/drivers/net/ethernet/mellanox/mlx5/core/events.c
> > index e92df7020a26..587d93ec905f 100644
> > +++ b/drivers/net/ethernet/mellanox/mlx5/core/events.c
> > @@ -157,23 +157,43 @@ static int temp_warn(struct notifier_block *nb, unsigned long type, void *data)
> > }
> >
> > /* MLX5_EVENT_TYPE_PORT_MODULE_EVENT */
> > -static const char *mlx5_pme_status[MLX5_MODULE_STATUS_NUM] = {
> > - "Cable plugged", /* MLX5_MODULE_STATUS_PLUGGED = 0x1 */
> > - "Cable unplugged", /* MLX5_MODULE_STATUS_UNPLUGGED = 0x2 */
> > - "Cable error", /* MLX5_MODULE_STATUS_ERROR = 0x3 */
> > -};
> > +static const char *mlx5_pme_status_to_string(enum port_module_event_status_type status)
> > +{
> > + switch (status) {
> > + case MLX5_MODULE_STATUS_PLUGGED:
> > + return "Cable plugged";
> > + case MLX5_MODULE_STATUS_UNPLUGGED:
> > + return "Cable unplugged";
> > + case MLX5_MODULE_STATUS_ERROR:
> > + return "Cable error";
> > + default:
> > + return "Unknown status";
> > + }
> > +}
>
> Arrays are usually a bette codegen bet than switch/case unless the array is
> very sparse, but it should be written as
>
> [MLX5_MODULE_STATUS_PLUGGED] = "Cable plugged",
>
> Commit message should explain why this is being converted. Maybe it is
> very sparse?
>

In the next patch it will become sparse, due to:
MLX5_MODULE_EVENT_ERROR_PCIE_POWER_SLOT_EXCEEDED = 0xc,

and it will need some corner case handling to report "unknown" for the gaps.
I tend to agree that arrays are better but in this case they demanded
more code to handle corner cases
in the next patches.

> Jason