[Intel-gfx] [PATCH] drm/i915/skl: Assume no scaling is available when things are not as expected

[Daniel Vetter]

On Mon, Jun 01, 2015 at 01:04:37PM +0100, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> Cdclk < crtc_clock is not allowed and suggests a different problem elsewhere.
> 
> It is more robust and safe to assume no scaling is possible in this case.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 93a5e51..4c99373 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -13234,7 +13234,7 @@ skl_max_scale(struct intel_crtc *intel_crtc, struct intel_crtc_state *crtc_state
>  	crtc_clock = crtc_state->base.adjusted_mode.crtc_clock;
>  	cdclk = dev_priv->display.get_display_clock_speed(dev);

Probably fallout from the in-flight dynamic cdclk stuff - this code checks
the wrong bits I guess. Chandra?

Thanks, Daniel

>  
> -	if (!crtc_clock || !cdclk)
> +	if (!crtc_clock || !cdclk || (cdclk < crtc_clock))
>  		return DRM_PLANE_HELPER_NO_SCALING;
>  
>  	/*
> -- 
> 2.4.0
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

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