On Fri, Oct 16, 2020 at 7:02 PM Melissa Wen <melissa.srw@xxxxxxxxx> wrote: > > On 10/16, Daniel Vetter wrote: > > On Fri, Oct 16, 2020 at 12:38 PM Simon Ser <contact@xxxxxxxxxxx> wrote: > > > > > > > The only thing we support is xrgb8888. > > > > > > > > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> > > > > Cc: Rodrigo Siqueira <rodrigosiqueiramelo@xxxxxxxxx> > > > > Cc: Melissa Wen <melissa.srw@xxxxxxxxx> > > > > Cc: Haneen Mohammed <hamohammed.sa@xxxxxxxxx> > > > > Cc: Daniel Vetter <daniel@xxxxxxxx> > > > > --- > > > > drivers/gpu/drm/vkms/vkms_drv.c | 2 +- > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c > > > > index 726801ab44d4..eb4007443706 100644 > > > > --- a/drivers/gpu/drm/vkms/vkms_drv.c > > > > +++ b/drivers/gpu/drm/vkms/vkms_drv.c > > > > @@ -124,7 +124,7 @@ static int vkms_modeset_init(struct vkms_device *vkmsdev) > > > > dev->mode_config.max_height = YRES_MAX; > > > > dev->mode_config.cursor_width = 512; > > > > dev->mode_config.cursor_height = 512; > > > > - dev->mode_config.preferred_depth = 24; > > > > + dev->mode_config.preferred_depth = 32; > > > > > > Are you sure xrgb8888's depth is 32 and not 24? Looking at drmdb [1], *all* > > > drivers set it to 24. > > > > Uh there's a problem I think. Depth should indeed stay at 24, the > > problem is that fb helpers directly take that to be the bpp parameter, > > which is a different thing. And if you look at how most drivers set up > > that, they pick 32. > > > > I guess I need to revert this here, and unconfuse the fb helpers about > > depth vs bpp. > > Hi guys, > > Perhaps it deserves to be pointed out: the documentation says > "preferred_depth: preferred RBG(sic) pixel depth, used by fb helpers", > and looking to fb helpers, preferred_depth is only used by > generic_setup, as bits by pixel (if I didn't miss something there). > > In fact, the alpha channel is not used for final display (perhaps in the > future); however, I saw another driver with a change similar to this > here and, possibly like me, following the same misunderstanding. Yeah the problem is that preferred_depth is depth, and that means 24 bit for XRGB8888. But bpp as used by fb helpers would be 32 bit for XRGB8888. I think the real fix here is to switch this entire mess over to using drm_fourcc codes directly, at least for atomic drivers. Which nowadays are most. Interim I'm not sure whether we should revert my patch (it breaks fbdev) or switch preferred_depth to 0, which means we get the default every, and that means both fbdev helpers and userspace will pick XRGB8888. -Daniel > Melissa > > > > Maybe best would be to just switch over to preferred drm_fourcc format > > code, or maybe just pick this up from the first format the primary > > plane supports. > > > > This is all getting slightly tricky and a lot more work :-/ > > -Daniel > > -- > > Daniel Vetter > > Software Engineer, Intel Corporation > > http://blog.ffwll.ch -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
