On Fri, Feb 03, 2023 at 02:52:50PM +0100, Sebastian Wick wrote: > On Fri, Feb 3, 2023 at 2:35 PM Ville Syrjälä > <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > > > > On Fri, Feb 03, 2023 at 01:59:07PM +0100, Sebastian Wick wrote: > > > On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > > > <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > > > > > > > > On Fri, Feb 03, 2023 at 02:07:44AM +0000, Joshua Ashton wrote: > > > > > Userspace has no way of controlling or knowing the pixel encoding > > > > > currently, so there is no way for it to ever get the right values here. > > > > > > > > That applies to a lot of the other values as well (they are > > > > explicitly RGB or YCC). The idea was that this property sets the > > > > infoframe/MSA/SDP value exactly, and other properties should be > > > > added to for use userspace to control the pixel encoding/colorspace > > > > conversion(if desired, or userspace just makes sure to > > > > directly feed in correct kind of data). > > > > > > I'm all for getting userspace control over pixel encoding but even > > > then the kernel always knows which pixel encoding is selected and > > > which InfoFrame has to be sent. Is there a reason why userspace would > > > want to control the variant explicitly to the wrong value? > > > > What do you mean wrong value? Userspace sets it based on what > > kind of data it has generated (or asked the display hardware > > to generate if/when we get explicit control over that part). > > Wrong in the sense of sending the YCC variant when the pixel encoding > is RGB for example. > > Maybe I'm missing something here but my assumption is that the kernel > always has to know the pixel encoding anyway. The color pipeline also > assumes that the pixel values are RGB. User space might be able to > generate YCC content but for subsampling etc the pixel encoding still > has to be explicitly set. The kernel doesn't really know much atm. In theory you can just configure the thing to do a straight passthough and put anything you want into your pixels. > > So with the kernel always knowing exactly what pixel encoding is sent, > why do we need those variants? I just don't see why this is necessary. > > > > > -- > > Ville Syrjälä > > Intel > > -- Ville Syrjälä Intel
