diff mbox series

[2/2] drm/i915: Require FEC for DSC on DP-MST

Message ID 20230913150356.9477-2-ville.syrjala@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series [1/2] drm/i915: Check lane count when determining FEC support | expand

Commit Message

Ville Syrjälä Sept. 13, 2023, 3:03 p.m. UTC
From: Ville Syrjälä <ville.syrjala@linux.intel.com>

The current check just asserts that we need FEC to use DSC
with (non-eDP) DP-SST. But MST also needs FEC for DSC. Just
check for !eDP instead to cover all the cases correctly.

Cc: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Jani Nikula Sept. 20, 2023, 9:20 a.m. UTC | #1
On Wed, 13 Sep 2023, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> The current check just asserts that we need FEC to use DSC
> with (non-eDP) DP-SST. But MST also needs FEC for DSC. Just
> check for !eDP instead to cover all the cases correctly.

128b/132b won't have crtc->fec_enable set, as it's part of channel
encoding. We don't need to explicitly enable it in hardware, the
128b/132b bandwidth computations take it into account in the equation,
but we can't skip DSC based on !crtc_state->fec_enable either.

BR,
Jani.


>
> Cc: Luca Coelho <luciano.coelho@intel.com>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  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 2cde8ac513bb..41f180f2879e 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -1380,7 +1380,7 @@ static bool intel_dp_supports_fec(struct intel_dp *intel_dp,
>  static bool intel_dp_supports_dsc(struct intel_dp *intel_dp,
>  				  const struct intel_crtc_state *crtc_state)
>  {
> -	if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP) && !crtc_state->fec_enable)
> +	if (!intel_dp_is_edp(intel_dp) && !crtc_state->fec_enable)
>  		return false;
>  
>  	return intel_dsc_source_support(crtc_state) &&
Ville Syrjälä Sept. 20, 2023, 11:09 a.m. UTC | #2
On Wed, Sep 20, 2023 at 12:20:51PM +0300, Jani Nikula wrote:
> On Wed, 13 Sep 2023, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >
> > The current check just asserts that we need FEC to use DSC
> > with (non-eDP) DP-SST. But MST also needs FEC for DSC. Just
> > check for !eDP instead to cover all the cases correctly.
> 
> 128b/132b won't have crtc->fec_enable set, as it's part of channel
> encoding. We don't need to explicitly enable it in hardware, the
> 128b/132b bandwidth computations take it into account in the equation,
> but we can't skip DSC based on !crtc_state->fec_enable either.

Hmm. Right. I suppose we need a uhbr check here as well then.

> 
> BR,
> Jani.
> 
> 
> >
> > Cc: Luca Coelho <luciano.coelho@intel.com>
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  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 2cde8ac513bb..41f180f2879e 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -1380,7 +1380,7 @@ static bool intel_dp_supports_fec(struct intel_dp *intel_dp,
> >  static bool intel_dp_supports_dsc(struct intel_dp *intel_dp,
> >  				  const struct intel_crtc_state *crtc_state)
> >  {
> > -	if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP) && !crtc_state->fec_enable)
> > +	if (!intel_dp_is_edp(intel_dp) && !crtc_state->fec_enable)
> >  		return false;
> >  
> >  	return intel_dsc_source_support(crtc_state) &&
> 
> -- 
> Jani Nikula, Intel
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 2cde8ac513bb..41f180f2879e 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1380,7 +1380,7 @@  static bool intel_dp_supports_fec(struct intel_dp *intel_dp,
 static bool intel_dp_supports_dsc(struct intel_dp *intel_dp,
 				  const struct intel_crtc_state *crtc_state)
 {
-	if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP) && !crtc_state->fec_enable)
+	if (!intel_dp_is_edp(intel_dp) && !crtc_state->fec_enable)
 		return false;
 
 	return intel_dsc_source_support(crtc_state) &&