Re: [PATCH 12/23] drm: omapdrm: plane: update fifo size on atomic update

Laurent Pinchart
2016-12-14T09:09:39Z

Hi Tomi,

On Wednesday 14 Dec 2016 10:43:18 Tomi Valkeinen wrote:
> On 13/12/16 19:35, Laurent Pinchart wrote:
> > On Tuesday 08 Mar 2016 17:39:44 Sebastian Reichel wrote:
> >> This is a workaround for a hardware bug occuring
> >> on OMAP3 with manually updated panels.
> >
> > Could you please explain what the bug is and how the workaround operates ?
> > Do you have a reference to an errata document ?
>
> I don't think I ever found out exactly why the problem happens. But on
> OMAP3 DSI, the fifo thresholds had to be tuned slightly, otherwise DISPC
> would stop. dispc_ovl_compute_fifo_thresholds() does that tuning if
> "manual_update" parameter is set on OMAP3.

I've had a look at dispc_ovl_compute_fifo_thresholds() and the patch makes
sense to me. If Sebastian could address the small issues I pointed out, we
could then merge this. Alternatively I can take care of addressing them.

--
Regards,

Laurent Pinchart