Re: [PATCH v2 2/5] drm/tegra: Add plane support

[Lucas Stach <dev-8ppwABl0HbeELgA04lAiVw@public.gmane.org>]

Am Dienstag, den 15.01.2013, 17:53 +0800 schrieb Mark Zhang:
> On 01/15/2013 12:05 AM, Thierry Reding wrote:
> > Add support for the B and C planes which support RGB and YUV pixel
> > formats and can be used as overlays or hardware cursor.
> 
> I think "hardware cursor" has specific meaning for Tegra(e.g: Tegra30
> has a 32x32 24bpp or 64x64 2bpp hardware cursor). So you may change it
> to "hardware accelerated cursor"?
> 
According to the TRM no Tegra has ARGB hardware cursor support, but only
2-color. So we talked about doing the hardware cursor by using a plane.
If the TRM is wrong in this regard and we can get a ARGB cursor on Tegra
3 it would be nice to know.

> > 
> > Signed-off-by: Thierry Reding <thierry.reding-RM9K5IK7kjKj5M59NBduVrNAH6kLmebB@public.gmane.org>
> > ---
> [...]
> > +};
> > +
> > +static int tegra_dc_add_planes(struct drm_device *drm, struct tegra_dc *dc)
> > +{
> > +	unsigned int i;
> > +	int err = 0;
> > +
> > +	for (i = 0; i < 2; i++) {
> > +		struct tegra_plane *plane;
> > +
> > +		plane = devm_kzalloc(drm->dev, sizeof(*plane), GFP_KERNEL);
> > +		if (!plane)
> > +			return -ENOMEM;
> > +
> > +		plane->index = i;
> 
> I suggest to change this line to: "plane->index = i + 1;". This makes
> the plane's index be consistent with Tegra's windows number. And also we
> don't need to worry about passing "plane->index + 1" to some functions
> which need to know which window is operating on.
> 
Again, if we make WIN_C the root window, we can keep the plane index
assignment as is and get rid of the "index + 1" passing.