[Intel-gfx] [PATCH] drm/i915/cnl: Don't trust VBT's alternate pin for port D for now.

[Clint Taylor]

On 07/06/2017 02:08 PM, Rodrigo Vivi wrote:
> Cannon Lake's VBT that is currently available for B0 stepping
> states that port D uses alternate pin 3 messing up with the
> default pin-port mapping table. Using that information we cannot
> get HDMI working properly. So for now we don't relly on VBT for
> this information.
>
> Cc: Clint Taylor <clinton.a.taylor at intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> ---
>   drivers/gpu/drm/i915/intel_bios.c | 9 +++++++++
>   1 file changed, 9 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> index 639d45c..82b144c 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -1187,6 +1187,15 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
>   	if (is_dvi) {
>   		info->alternate_ddc_pin = ddc_pin;
>   
> +		/*
> +		 * All VBTs that we got so far for B Stepping has this
> +		 * information wrong for Port D. So, let's just ignore for now.
> +		 */
> +		if (IS_CNL_REVID(dev_priv, CNL_REVID_B0, CNL_REVID_B0) &&
> +		    port == PORT_D) {
> +			info->alternate_ddc_pin = 0;
> +		}
> +

Reviewed-by: Clinton Taylor <clinton.a.taylor at intel.com>

-Clint

>   		sanitize_ddc_pin(dev_priv, port);
>   	}
>