[PATCH v2] drm: xlnx: zynqmp_dpsub: Enable plane in atomic update

[Klymenko, Anatoliy]

> -----Original Message-----
> From: Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
> Sent: Monday, June 17, 2024 12:44 AM
> To: Klymenko, Anatoliy <Anatoliy.Klymenko at amd.com>; Laurent Pinchart
> <laurent.pinchart at ideasonboard.com>; Maarten Lankhorst
> <maarten.lankhorst at linux.intel.com>; Maxime Ripard
> <mripard at kernel.org>; Thomas Zimmermann <tzimmermann at suse.de>;
> David Airlie <airlied at gmail.com>; Daniel Vetter <daniel at ffwll.ch>;
> Simek, Michal <michal.simek at amd.com>
> Cc: dri-devel at lists.freedesktop.org; linux-arm-kernel at lists.infradead.org;
> linux-kernel at vger.kernel.org
> Subject: Re: [PATCH v2] drm: xlnx: zynqmp_dpsub: Enable plane in atomic
> update
> 
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> 
> 
> Hi,
> 
> On 24/05/2024 02:49, Anatoliy Klymenko wrote:
> > Unconditionally enable the DPSUB layer in the corresponding atomic
> plane
> > update callback. Setting the new display mode may require disabling
> and
> > re-enabling the CRTC. This effectively resets DPSUB to the default state
> > with all layers disabled. The original implementation of the plane
> atomic
> > update enables the corresponding DPSUB layer only if the framebuffer
> > format has changed. This would leave the layer disabled after switching
> to
> > a different display mode with the same framebuffer format.
> >
> > Signed-off-by: Anatoliy Klymenko <anatoliy.klymenko at amd.com>
> > ---
> > Changes in v2:
> > - Added comment around DPSUB layer enablement explaining why it
> should be
> >    done unconditionally.
> > - Link to v1: https://lore.kernel.org/r/20240520-dp-layer-enable-v1-1-
> c9b481209115 at amd.com
> > ---
> >   drivers/gpu/drm/xlnx/zynqmp_kms.c | 10 +++++++---
> >   1 file changed, 7 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/xlnx/zynqmp_kms.c
> b/drivers/gpu/drm/xlnx/zynqmp_kms.c
> > index 43bf416b33d5..0b57ab5451a9 100644
> > --- a/drivers/gpu/drm/xlnx/zynqmp_kms.c
> > +++ b/drivers/gpu/drm/xlnx/zynqmp_kms.c
> > @@ -120,9 +120,13 @@ static void
> zynqmp_dpsub_plane_atomic_update(struct drm_plane *plane,
> >               zynqmp_disp_blend_set_global_alpha(dpsub->disp, true,
> >                                                  plane->state->alpha >> 8);
> >
> > -     /* Enable or re-enable the plane if the format has changed. */
> > -     if (format_changed)
> > -             zynqmp_disp_layer_enable(layer);
> > +     /*
> > +      * Unconditionally enable the layer, as it may have been disabled
> > +      * previously either explicitly to reconfigure layer format, or
> > +      * implicitly after DPSUB reset during display mode change. DRM
> > +      * framework calls this callback for enabled planes only.
> > +      */
> > +     zynqmp_disp_layer_enable(layer);
> >   }
> >
> >   static const struct drm_plane_helper_funcs
> zynqmp_dpsub_plane_helper_funcs = {
> >
> > ---
> > base-commit: 673087d8b023faf34b84e8faf63bbeea3da87bab
> > change-id: 20240520-dp-layer-enable-7b561af29ca8
> >
> > Best regards,
> 
> Thanks, I have pushed this to drm-misc-next.
> 
>   Tomi

Thank you,
Anatoliy