Hi,
On Tue, Jul 30, 2019 at 01:37:51PM +0200, Pavel Machek wrote:
> On Mon 2019-07-29 21:20:44, Greg Kroah-Hartman wrote:
> > [ Upstream commit ad9df7d91b4a6e8f4b20c2bf539ac09b3b2ad6eb ]
> >
> > While most display types only forward their VM to the DISPC, this
> > is not true for DSI. DSI calculates the VM for DISPC based on its
> > own, but it's not identical. Actually the DSI VM is not even a valid
> > DISPC VM making this check fail. Let's restore the old behaviour
> > and avoid checking the DISPC VM for DSI here.
> >
> > Fixes: 7c27fa57ef31 ("drm/omap: Call dispc timings check operation directly")
> > Acked-by: Pavel Machek <pavel@xxxxxx>
> > Tested-by: Tony Lindgren <tony@xxxxxxxxxxx>
> > Tested-by: Pavel Machek <pavel@xxxxxx>
> > Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
> > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
>
> Not sure if this is good idea for stable. IIRC there's series of
> patches to enable display on droid4 (etc), which is useful, but this
> patch is not going to do any good on its own.
It does not hurt to have it. I know that some people have out of
tree omapdrm DSI drivers and those also need this regression fix.
-- Sebastian
>
> Pavel
>
> > drivers/gpu/drm/omapdrm/omap_crtc.c | 18 ++++++++++++++----
> > 1 file changed, 14 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c b/drivers/gpu/drm/omapdrm/omap_crtc.c
> > index 8712af79a49c..4c43dd282acc 100644
> > --- a/drivers/gpu/drm/omapdrm/omap_crtc.c
> > +++ b/drivers/gpu/drm/omapdrm/omap_crtc.c
> > @@ -384,10 +384,20 @@ static enum drm_mode_status omap_crtc_mode_valid(struct drm_crtc *crtc,
> > int r;
> >
> > drm_display_mode_to_videomode(mode, &vm);
> > - r = priv->dispc_ops->mgr_check_timings(priv->dispc, omap_crtc->channel,
> > - &vm);
> > - if (r)
> > - return r;
> > +
> > + /*
> > + * DSI might not call this, since the supplied mode is not a
> > + * valid DISPC mode. DSI will calculate and configure the
> > + * proper DISPC mode later.
> > + */
> > + if (omap_crtc->pipe->output->next == NULL ||
> > + omap_crtc->pipe->output->next->type != OMAP_DISPLAY_TYPE_DSI) {
> > + r = priv->dispc_ops->mgr_check_timings(priv->dispc,
> > + omap_crtc->channel,
> > + &vm);
> > + if (r)
> > + return r;
> > + }
> >
> > /* Check for bandwidth limit */
> > if (priv->max_bandwidth) {
>
> --
> (english) http://www.livejournal.com/~pavelmachek
> (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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