Re: [Intel-gfx] [PATCH] drm/i915/hdmi: Prune Interlaced modes for Display >= 12

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Thu, Oct 13, 2022 at 05:29:39PM +0530, Nautiyal, Ankit K wrote:
> 
> On 10/13/2022 4:00 PM, Ville Syrjälä wrote:
> > On Thu, Oct 13, 2022 at 10:41:24AM +0530, Ankit Nautiyal wrote:
> >> Defeature Display Interlace support.
> >> Support for Interlace modes is removed from Gen 12 onwards.
> >> For DP we do not support interlace modes (except for very old
> >> platforms).
> > Yes we do. Specifically G4X/VLV/CHV do not support it,
> > everything else does.
> 
> You are right. I think I misread the condition for DP and came to wrong 
> conclusion.
> 
> Will need to add the condition for DP as well in that case.
> 
> Apologies for the confusion, and thanks for pointing it out.
> 
> >
> >> Pruning the interlaced modes for HDMI for Display >=12.
> >> Bspec: 50490
> > The tagging there seems borked. Only ADLS shows it as not supported.
> 
> Yes the page is getting updated it seems. The HSDES for this reads 
> affected platform as 12 and beyond.
> 
> 
> >
> >> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> >> ---
> >>   drivers/gpu/drm/i915/display/intel_hdmi.c | 11 ++++++++++-
> >>   1 file changed, 10 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
> >> index 93519fb23d9d..791bfb062c49 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_hdmi.c
> >> +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
> >> @@ -1990,6 +1990,9 @@ intel_hdmi_mode_valid(struct drm_connector *connector,
> >>   	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
> >>   		return MODE_NO_DBLESCAN;
> >>   
> >> +	if (DISPLAY_VER(dev_priv) >= 12 && mode->flags & DRM_MODE_FLAG_INTERLACE)
> >> +		return MODE_NO_INTERLACE;
> >> +
> > These are pointless if the connector doesn't declare interlace_allowed
> > anyway.
> 
> You are right,  will drop this from mode valid then.
> 
> As an aside, I see, we do not set connector double_scan allowed, so  the 
> above condition from mode_valid can also be removed I think.

Yeah, looks like I mistakenly added those when dealing with the
Xorg doublescan mess. Probably just forgot that doublescan_allowed
was even a thing.

-- 
Ville Syrjälä
Intel