[PATCH] drm/i915/dp: Return min bpc supported by source instead of 0

[Rodrigo Vivi]

On Fri, Jan 31, 2025 at 01:10:25AM -0500, Borah, Chaitanya Kumar wrote:
> 
> 
> > -----Original Message-----
> > From: Intel-xe <intel-xe-bounces at lists.freedesktop.org> On Behalf Of Ankit
> > Nautiyal
> > Sent: Friday, January 31, 2025 9:44 AM
> > To: intel-gfx at lists.freedesktop.org; intel-xe at lists.freedesktop.org
> > Cc: jani.nikula at linux.intel.com; Kandpal, Suraj <suraj.kandpal at intel.com>;
> > Vivi, Rodrigo <rodrigo.vivi at intel.com>; david.laight.linux at gmail.com;
> > naresh.kamboju at linaro.org
> > Subject: [PATCH] drm/i915/dp: Return min bpc supported by source instead
> > of 0
> > 
> > Currently, intel_dp_dsc_max_src_input_bpc can return 0 for platforms not
> > supporting DSC, which could theoretically cause issues in clamp() due to a
> > low limit being greater than the high limit.
> > 
> > Instead, return the minimum bpc supported by the source to prevent such
> > issues.
> > 
> > Reported-by: Linux Kernel Functional Testing <lkft at linaro.org>
> > Closes:
> > https://lore.kernel.org/all/CA+G9fYtNfM399_=_ff81zeRJv=0+z7oFJfPGmJgTp6y
> > rJmU+1w at mail.gmail.com/
> > Fixes: 160672b86b0d ("drm/i915/dp: Use clamp for pipe_bpp limits with
> > DSC")
> > Cc: Suraj Kandpal <suraj.kandpal at intel.com>
> > Cc: Jani Nikula <jani.nikula at linux.intel.com>
> > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
> 
> Solves the build issue for linux-next.
> 
> Tested-by: Chaitanya Kumar Borah <chaitanya.kumar.borah at intel.com>

pushed to drm-intel-next. Thank you all

> 
> 
> 
> > ---
> >  drivers/gpu/drm/i915/display/intel_dp.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> > b/drivers/gpu/drm/i915/display/intel_dp.c
> > index 80214a559013..d28abf081844 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -1791,7 +1791,7 @@ int intel_dp_dsc_max_src_input_bpc(struct
> > intel_display *display)
> >  	if (DISPLAY_VER(display) == 11)
> >  		return 10;
> > 
> > -	return 0;
> > +	return intel_dp_dsc_min_src_input_bpc();
> >  }
> > 
> >  int intel_dp_dsc_compute_max_bpp(const struct intel_connector *connector,
> > --
> > 2.45.2
>