Hi Tomi, On 20 April 2018 at 08:09, Tomi Valkeinen <tomi.valkeinen@xxxxxx> wrote: > It's actually not quite clear to me how manual update displays work with > DRM... > > As far as I see, we have essentially two cases: 1) single buffering, > where the userspace must set an area in the fb dirty, which then > triggers the update, 2) multi buffering, which doesn't need fb dirty, > but just a page flip which triggers the update. > > In the 2) case (which I think is the optimal case which all the modern > apps should use), there's no need for delayed work or any work, and the > code flow should be very similar to the auto-update model. Correct. There's been talk (and I think patches?) of adding a per-plane dirty property, so userspace can as an optimisation inform the kernel of the area changed between frames. But short of that, a pageflip needs to trigger a full-plane update, with no dirtyfb required. Cheers, Daniel -- 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
