Re: [Intel-gfx] [PATCH 2/2] drm/i915: Require FEC for DSC on DP-MST
On Wed, Sep 20, 2023 at 12:20:51PM +0300, Jani Nikula wrote:
> On Wed, 13 Sep 2023, Ville Syrjala wrote:
> > From: Ville Syrjälä
> >
> > 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
> > Signed-off-by: Ville Syrjälä
> > ---
> > 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
--
Ville Syrjälä
Intel
Re: [Intel-gfx] [PATCH 2/2] drm/i915: Require FEC for DSC on DP-MST
On Wed, 13 Sep 2023, Ville Syrjala wrote:
> From: Ville Syrjälä
>
> 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
> Signed-off-by: Ville Syrjälä
> ---
> 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
[Intel-gfx] [PATCH 2/2] drm/i915: Require FEC for DSC on DP-MST
From: Ville Syrjälä
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
Signed-off-by: Ville Syrjälä
---
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) &&
--
2.41.0
