On Mon, 21 Jul 2014 15:47:52 +0200 Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > Hi Boris, > > On Monday 21 July 2014 15:43:13 Boris BREZILLON wrote: > > On Mon, 21 Jul 2014 15:30:35 +0200 Thierry Reding wrote: > > > On Mon, Jul 21, 2014 at 03:22:05PM +0200, Laurent Pinchart wrote: > > >> On Monday 21 July 2014 14:55:23 Thierry Reding wrote: > > >>> On Mon, Jul 21, 2014 at 02:34:28PM +0200, Boris BREZILLON wrote: > > >>>> On Mon, 21 Jul 2014 14:16:42 +0200 Laurent Pinchart wrote: > > >>>>> On Monday 21 July 2014 14:12:47 Thierry Reding wrote: > > >>>>>> On Mon, Jul 21, 2014 at 11:57:37AM +0200, Boris BREZILLON wrote: > > >> > > >> [snip] > > >> > > >>>>>>> The new drm_display_info structure should look like this [2] > > >>>>>>> (except that color_formats and bpc have not be removed yet), and > > >>>>>>> [1] is just here to show how the video_bus_format enum would look > > >>>>>>> like. > > >>>>>>> > > >>>>>>> [1] http://code.bulix.org/rfd0yx-86557 > > >>>>>>> [2] http://code.bulix.org/7n03b4-86556 > > >>>>>> > > >>>>>> Quoting from your paste: > > >>>>>> + const enum video_bus_format *bus_formats; > > >>>>>> + int nbus_formats; > > >>>>>> > > >>>>>> Do we really need more than one? > > >>>>> > > >>>>> We do if we want to replace the color_formats and bpc fields. > > >>>> > > >>>> Yes, that's what I was about to answer :-). > > >>> > > >>> Maybe we don't need to replace color_formats and bpc field > > >>> immediately. That could be done in a follow-up patch. > > >> > > >> We don't need to replace them right now, but we should at least agree on > > >> how to replace them. Introducing a new field that would need to be > > >> replaced in the near future when removing color_formats and bpc would > > >> be a waste of time. > > > > > > Sure. One of the problems I see with replacing color_formats and bpc > > > with the above is that some of the bits within color_formats are set > > > when the EDID is parsed. That implies that if they are replaced with > > > an array of formats, the array would need to be reallocated during EDID > > > parsing. That sounds like ugliness. > > > > > > But if you can find a nice way to make it work that'd be great. > > > > How about using a list instead of an array ? > > This way we can add elements to this list when parsing the EDID. > > > > Or we can just define a maximum size for the bus_formats array when > > retrieving this info from EDID. If I'm correct we have at most 18 bus > > formats: > > - 3 color formats: > > * RGB 4:4:4 > > * YCbCr 4:4:4 > > * YCbCr 4:4:2 > > - 6 color depths: 6, 8, 10, 12, 14 and 16 bits per color > > bpc isn't a bitmask, so EDID supports up to three formats only. Yes, bpc only contains a single value for now, and it fits the DRM_EDID_DIGITAL_DEPTH field [1] (an enum defining the supported pixel depth). ITOH, DRM_EDID_HDMI_DC_XX [2] (which are referenced in the new drm_assign_hdmi_deep_color_info function) are just bitmasks and thus a display might support several color depth. As a result, I wonder if we shouldn't start supporting several color depths (as we do for color formats). [1]http://lxr.free-electrons.com/source/drivers/gpu/drm/drm_edid.c#L3436 [2]https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/gpu/drm/drm_edid.c?id=refs/tags/v3.16-rc6#n3440 -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
