[Intel-gfx] [PATCH] drm/i915/cnp: Ignore VBT request for know invalid DDC pin.

[Rodrigo Vivi]

On Tue, Jan 23, 2018 at 05:40:50PM +0000, Rodrigo Vivi wrote:
> Let's ignore VBT request if the pin is clearly wrong.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104139
> Cc: Kai Heng Feng <kai.heng.feng at canonical.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>

Reviewed-by: Radhakrishna Sripada <radhakrishna.sripada at intel.com>
(f2f)
thanks

merged to dinq.

> ---
>  drivers/gpu/drm/i915/intel_bios.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> index b0668202dc7e..95f0b310d656 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -1115,9 +1115,14 @@ static const u8 cnp_ddc_pin_map[] = {
>  
>  static u8 map_ddc_pin(struct drm_i915_private *dev_priv, u8 vbt_pin)
>  {
> -	if (HAS_PCH_CNP(dev_priv) &&
> -	    vbt_pin > 0 && vbt_pin < ARRAY_SIZE(cnp_ddc_pin_map))
> -		return cnp_ddc_pin_map[vbt_pin];
> +	if (HAS_PCH_CNP(dev_priv)) {
> +		if (vbt_pin > 0 && vbt_pin < ARRAY_SIZE(cnp_ddc_pin_map))
> +			return cnp_ddc_pin_map[vbt_pin];
> +		if (vbt_pin > GMBUS_PIN_4_CNP) {
> +			DRM_DEBUG_KMS("Ignoring alternate pin: VBT claims DDC pin %d, which is not valid for this platform\n", vbt_pin);
> +			return 0;
> +		}
> +	}
>  
>  	return vbt_pin;
>  }
> -- 
> 2.13.6
>