[Intel-gfx] [PATCH 2/2] drm/i915/edp: Increase the T12 delay quirk to 1300ms

[Daniel Vetter]

On Tue, Oct 03, 2017 at 04:37:25PM -0700, Manasi Navare wrote:
> For this specific PCI device, the eDP panel requires a higher
> panel power cycle delay of 1300ms where the minimum spec
> requirement of panel power cycle delay is 500ms.
> This fix in combination with correct timestamp at which we get the
> panel power off time fixes the dP AUX CH timeouts seen on various IGT tests.
> 
> Fixes: c99a259b4b5192ba ("drm/i915/edp: Add a T12 panel delay quirk to fix
> DP AUX CH timeouts")
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101144,
> https://bugs.freedesktop.org/show_bug.cgi?id=101518
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Jani Nikula <jani.nikula at linux.intel.com>
> Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
> Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>

I still wondere whether we can't match on something panel-specific from dp
aux, but as long as there's only one this should be ok. If there's more,
matching on dp aux and putting the quirks into drm_dp_helper.c would be
much better I think.

Acked-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
>  drivers/gpu/drm/i915/intel_dp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 0fd41cd..ca48bce 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -5286,7 +5286,7 @@ intel_dp_init_panel_power_sequencer(struct drm_device *dev,
>  	 * seems sufficient to avoid this problem.
>  	 */
>  	if (dev_priv->quirks & QUIRK_INCREASE_T12_DELAY) {
> -		vbt.t11_t12 = max_t(u16, vbt.t11_t12, 900 * 10);
> +		vbt.t11_t12 = max_t(u16, vbt.t11_t12, 1300 * 10);
>  		DRM_DEBUG_KMS("Increasing T12 panel delay as per the quirk to %d\n",
>  			      vbt.t11_t12);
>  	}
> -- 
> 2.1.4
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch