[PATCH v2] drm/modes: Apply video parameters with only reflect option

[Stephan Gerhold]

Hi Maxime,

On Mon, Dec 16, 2019 at 07:08:12PM +0100, Stephan Gerhold wrote:
> On Mon, Dec 16, 2019 at 07:27:25PM +0200, Ville Syrjälä wrote:
> > On Mon, Dec 16, 2019 at 06:10:17PM +0100, Stephan Gerhold wrote:
> > > At the moment, video mode parameters like video=540x960,reflect_x,
> > > (without rotation set) are not taken into account when applying the
> > > mode in drm_client_modeset.c.
> > 
> > A rotation value without exactly one rotation angle is illegal.
> > IMO the code should not generate a value like that in the first
> > place.
> > 

What do you think about Ville's comment?
Should we change the command line parser to generate ROTATE_0 when no
rotate option is specified? This would also require updating a few of
the test cases.

You added the code for parsing the rotation/reflection options,
so I thought I'd ask before I start working on this.

Thanks,
Stephan

> 
> You're right. I was thinking about this when creating this patch.
> But then I was not sure if "mode->rotation_reflection" is supposed to be
> a valid rotation value.The zero value is currently used to check
> if any rotation/reflection was specified at all:
> 
> [...]
> > > diff --git a/drivers/gpu/drm/drm_client_modeset.c b/drivers/gpu/drm/drm_client_modeset.c
> > > index 895b73f23079..cfebce4f19a5 100644
> > > --- a/drivers/gpu/drm/drm_client_modeset.c
> > > +++ b/drivers/gpu/drm/drm_client_modeset.c
> > > @@ -859,19 +859,23 @@ bool drm_client_rotation(struct drm_mode_set *modeset, unsigned int *rotation)
> > >  	 */
> > >  	cmdline = &connector->cmdline_mode;
> > >  	if (cmdline->specified && cmdline->rotation_reflection) {
> 
> I can try to make your suggested change in the cmdline parsing code,
> but since this sounds like a larger change I would appreciate
> some other opinions first.
> 
> Thanks,
> Stephan
> 
> > > 
> > > -		unsigned int cmdline_rest, panel_rest;
> > > -		unsigned int cmdline_rot, panel_rot;
> > > -		unsigned int sum_rot, sum_rest;
> > > +		if (cmdline->rotation_reflection & DRM_MODE_ROTATE_MASK) {
> > > +			unsigned int cmdline_rest, panel_rest;
> > > +			unsigned int cmdline_rot, panel_rot;
> > > +			unsigned int sum_rot, sum_rest;
> > >  
> > > -		panel_rot = ilog2(*rotation & DRM_MODE_ROTATE_MASK);
> > > -		cmdline_rot = ilog2(cmdline->rotation_reflection & DRM_MODE_ROTATE_MASK);
> > > -		sum_rot = (panel_rot + cmdline_rot) % 4;
> > > +			panel_rot = ilog2(*rotation & DRM_MODE_ROTATE_MASK);
> > > +			cmdline_rot = ilog2(cmdline->rotation_reflection & DRM_MODE_ROTATE_MASK);
> > > +			sum_rot = (panel_rot + cmdline_rot) % 4;
> > >  
> > > -		panel_rest = *rotation & ~DRM_MODE_ROTATE_MASK;
> > > -		cmdline_rest = cmdline->rotation_reflection & ~DRM_MODE_ROTATE_MASK;
> > > -		sum_rest = panel_rest ^ cmdline_rest;
> > > +			panel_rest = *rotation & ~DRM_MODE_ROTATE_MASK;
> > > +			cmdline_rest = cmdline->rotation_reflection & ~DRM_MODE_ROTATE_MASK;
> > > +			sum_rest = panel_rest ^ cmdline_rest;
> > >  
> > > -		*rotation = (1 << sum_rot) | sum_rest;
> > > +			*rotation = (1 << sum_rot) | sum_rest;
> > > +		} else {
> > > +			*rotation ^= cmdline->rotation_reflection;
> > > +		}
> > >  	}
> > >  
> > >  	/*
> > > @@ -879,7 +883,8 @@ bool drm_client_rotation(struct drm_mode_set *modeset, unsigned int *rotation)
> > >  	 * depending on the hardware this may require the framebuffer
> > >  	 * to be in a specific tiling format.
> > >  	 */
> > > -	if ((*rotation & DRM_MODE_ROTATE_MASK) != DRM_MODE_ROTATE_180 ||
> > > +	if (((*rotation & DRM_MODE_ROTATE_MASK) != DRM_MODE_ROTATE_0 &&
> > > +	     (*rotation & DRM_MODE_ROTATE_MASK) != DRM_MODE_ROTATE_180) ||
> > >  	    !plane->rotation_property)
> > >  		return false;
> > >  
> > > -- 
> > > 2.24.1
> > > 
> > > _______________________________________________
> > > dri-devel mailing list
> > > dri-devel at lists.freedesktop.org
> > > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> > 
> > -- 
> > Ville Syrjälä
> > Intel