[Intel-gfx] [PATCH v2 03/11] drm/i915: HDMI pixel clock check

[Mika Kahola]

On Thu, 2015-07-30 at 07:54 +0100, Chris Wilson wrote:
> On Thu, Jul 30, 2015 at 09:49:30AM +0300, Mika Kahola wrote:
> > It is possible the we request to have a mode that has
> > higher pixel clock than our HW can support. This patch
> > checks if requested pixel clock is lower than the one
> > supported by the HW. The requested mode is discarded
> > if we cannot support the requested pixel clock.
> > 
> > This patch applies to HDMI.
> > 
> > V2:
> > - removed computation for max dot clock
> > 
> > Signed-off-by: Mika Kahola <mika.kahola at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_hdmi.c | 9 ++++++++-
> >  1 file changed, 8 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> > index 70bad5b..b85efaa 100644
> > --- a/drivers/gpu/drm/i915/intel_hdmi.c
> > +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> > @@ -1191,15 +1191,22 @@ intel_hdmi_mode_valid(struct drm_connector *connector,
> >  {
> >  	struct intel_hdmi *hdmi = intel_attached_hdmi(connector);
> >  	struct drm_device *dev = intel_hdmi_to_dev(hdmi);
> > +	struct drm_i915_private *dev_priv = to_i915(dev);
> >  	enum drm_mode_status status;
> >  	int clock;
> > +	int max_pixclk = dev_priv->max_dotclk;
> >  
> >  	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
> >  		return MODE_NO_DBLESCAN;
> >  
> >  	clock = mode->clock;
> > -	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
> > +	if (mode->flags & DRM_MODE_FLAG_DBLCLK) {
> >  		clock *= 2;
> > +		max_pixclk *= 2;
> > +	}
> > +
> > +	if (clock > max_pixclk)
> > +		return MODE_CLOCK_HIGH;
> 
> Or do the test before the DBLCLK?
Yes, I could move the test before DBLCLK.

-Mika-

> -Chris
>