[Intel-gfx] [PATCH 1/2] drm/i915/dp: Do not set master_trans bit in bitmak if INVALID_TRANSCODER

[Manasi Navare]

On Thu, Jan 23, 2020 at 04:01:28PM +0200, Ville Syrjälä wrote:
> On Wed, Jan 22, 2020 at 04:24:14PM -0800, Manasi Navare wrote:
> > In the port sync mode, for the master crtc, the master_transcoder is INVALID.
> > In that case since its value is -1, do not set the bit in the bitmask.
> > 
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Fixes: d0eed1545fe7 ("drm/i915: Fix post-fastset modeset check for port sync")
> > Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
> 
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Thanks for the review, I think populating master transcoder in master would also need us
to change all the helpers for is_trans_port_sync_mode and the readout and the commit_modeset_enables logic.
Its doable but too risky to change at this point incase it causes any regressions.

Still assume your r-b on this?

Manasi
> 
> > ---
> >  drivers/gpu/drm/i915/display/intel_display.c | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> > index 878d331b9e8c..79f9054078ea 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > @@ -14649,8 +14649,10 @@ static int intel_atomic_check(struct drm_device *dev,
> >  		}
> >  
> >  		if (is_trans_port_sync_mode(new_crtc_state)) {
> > -			u8 trans = new_crtc_state->sync_mode_slaves_mask |
> > -				   BIT(new_crtc_state->master_transcoder);
> > +			u8 trans = new_crtc_state->sync_mode_slaves_mask;
> > +
> > +			if (new_crtc_state->master_transcoder != INVALID_TRANSCODER)
> > +				trans |= BIT(new_crtc_state->master_transcoder);
> >  
> >  			if (intel_cpu_transcoders_need_modeset(state, trans)) {
> >  				new_crtc_state->uapi.mode_changed = true;
> > -- 
> > 2.19.1
> 
> -- 
> Ville Syrjälä
> Intel