Re: [PATCH 1/4] drm/i915: Don't populate pipe_src_{w, h} multiple times

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

On Tue, Oct 01, 2013 at 09:03:52PM +0200, Daniel Vetter wrote:
> On Tue, Oct 01, 2013 at 04:13:28PM +0300, ville.syrjala@linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > If we ever end up doing the retry loop due to bandwidth constraints, we
> > would rewrite pipe_src_{w,n} based on adjusted_mode timings. But by that
> > time the encoder may have already replaced the adjusted_mode with a
> > fixed panel mode, which would then corrupt pipe_src_{w,h}.
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_display.c | 9 +++++----
> >  1 file changed, 5 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index a91f20a..a695888 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -8472,6 +8472,11 @@ intel_modeset_pipe_config(struct drm_crtc *crtc,
> >  	if (plane_bpp < 0)
> >  		goto fail;
> >  
> > +	/* Determine the real pipe dimensions */
> 
> I think it'll benefit clarity a bit if we'd use the requested mode
> here (even though we never really care about it's crtc timings anywhere
> else).

Yeah that could be more clear.

> 
> This needs more comment imo. What about the following instead?
> 
> "Determine the real pipe dimensions. Note that stereo modes can increase
> the actual pipe size due to the frame doubling and insertion of additional
> space for blanks between the frame. This is stored in the crtc timings. We
> use the requested mode to do this computation to clearly distinguish it
> from the adjusted mode, which can be changed by the connectors in the
> below retry loop."
> 

Sure. I'll slap that on and send a v2.

> Cheers, Daniel
> 
> > +	drm_mode_set_crtcinfo(&pipe_config->adjusted_mode, CRTC_STEREO_DOUBLE);
> > +	pipe_config->pipe_src_w = pipe_config->adjusted_mode.crtc_hdisplay;
> > +	pipe_config->pipe_src_h = pipe_config->adjusted_mode.crtc_vdisplay;
> > +
> >  encoder_retry:
> >  	/* Ensure the port clock defaults are reset when retrying. */
> >  	pipe_config->port_clock = 0;
> > @@ -8480,10 +8485,6 @@ encoder_retry:
> >  	/* Fill in default crtc timings, allow encoders to overwrite them. */
> >  	drm_mode_set_crtcinfo(&pipe_config->adjusted_mode, CRTC_STEREO_DOUBLE);
> >  
> > -	/* set_crtcinfo() may have adjusted hdisplay/vdisplay */
> > -	pipe_config->pipe_src_w = pipe_config->adjusted_mode.crtc_hdisplay;
> > -	pipe_config->pipe_src_h = pipe_config->adjusted_mode.crtc_vdisplay;
> > -
> >  	/* Pass our mode to the connectors and the CRTC to give them a chance to
> >  	 * adjust it according to limitations or connector properties, and also
> >  	 * a chance to reject the mode entirely.
> > -- 
> > 1.8.1.5
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch

-- 
Ville Syrjälä
Intel OTC