[Intel-gfx] [PATCH] drm/i915/cnp: Properly handle VBT ddc pin out of bounds.

[Jani Nikula]

On Thu, 25 Jan 2018, Rodrigo Vivi <rodrigo.vivi at intel.com> wrote:
> If the table result is out of bounds on the array map
> there is something really wrong with VBT pin so we don't
> return that vbt_pin, but only return 0 instead.
>
> This basically reverts commit 'a8e6f3888b05 ("drm/i915/cnp:
> Ignore VBT request for know invalid DDC pin.")'
>
> Also this properly fixes commit 9c3b2689d01f ("drm/i915/cnl:
> Map VBT DDC Pin to BSpec DDC Pin.")
>
> v2: Do in a way that we don't break other platforms. (Jani)
>
> Fixes: a8e6f3888b05 ("drm/i915/cnp: Ignore VBT request for know invalid DDC pin.")
> Fixes: 9c3b2689d01f ("drm/i915/cnl: Map VBT DDC Pin to BSpec DDC Pin.")
> Cc: Radhakrishna Sripada <radhakrishna.sripada at intel.com>
> Cc: Jani Nikula <jani.nikula at intel.com>
> Cc: Kai Heng Feng <kai.heng.feng at canonical.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_bios.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> index 95f0b310d656..ad5a03028060 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -1118,10 +1118,8 @@ static u8 map_ddc_pin(struct drm_i915_private *dev_priv, u8 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);

I guess I'd keep the debug message, but either way,

Reviewed-by: Jani Nikula <jani.nikula at intel.com>


> +		else
>  			return 0;
> -		}
>  	}
>  
>  	return vbt_pin;

-- 
Jani Nikula, Intel Open Source Technology Center