[Intel-gfx] [PATCH 1/2] Give up on edid retries when i2c tells us that bus is not there

[Dave Airlie]

> This allows to avoid talking to a non-existent bus repeatedly until we
> finally timeout. The non-existent bus is signalled by -ENXIO error,
> provided by i2c_algo_bit:bit_doAddress call.
>
> As the advantage of such change, all the other routines which use
> drm_get_edid would benefit for this timeout.
>
> This change should fix
> https://bugs.freedesktop.org/show_bug.cgi?id=41059 and improve overall
> edid detection timing by 10-30% in most cases, and by a much larger margin
> in case of phantom outputs.

Jean, Alex,

I'm thinking of thowing this into -next, any objections?

Dave.

>
> Signed-off-by: Eugeni Dodonov <eugeni.dodonov at intel.com>
> ---
>  drivers/gpu/drm/drm_edid.c |    5 +++++
>  1 files changed, 5 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 7425e5c..1bca6d7 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -265,6 +265,11 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
>                        }
>                };
>                ret = i2c_transfer(adapter, msgs, 2);
> +               if (ret == -ENXIO) {
> +                       DRM_DEBUG_KMS("drm: skipping non-existent adapter %s\n",
> +                                       adapter->name);
> +                       break;
> +               }
>        } while (ret != 2 && --retries);
>
>        return ret == 2 ? 0 : -1;
> --
> 1.7.7
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>