linux-kernel - Re: [PATCH v2 1/2] drm/bridge-connector: reset the HDMI connector state

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Message-ID: <CAA8EJpr+fB4P=X_ufkggizqk5AW5P+HKsQO5FvjqXxg6x+m5vA@mail.gmail.com>
Date: Tue, 25 Jun 2024 01:31:36 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Abhinav Kumar <quic_abhinavk@...cinc.com>
Cc: Andrzej Hajda <andrzej.hajda@...el.com>, Neil Armstrong <neil.armstrong@...aro.org>, 
	Robert Foss <rfoss@...nel.org>, Laurent Pinchart <Laurent.pinchart@...asonboard.com>, 
	Jonas Karlman <jonas@...boo.se>, Jernej Skrabec <jernej.skrabec@...il.com>, 
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, Maxime Ripard <mripard@...nel.org>, 
	Thomas Zimmermann <tzimmermann@...e.de>, David Airlie <airlied@...il.com>, Daniel Vetter <daniel@...ll.ch>, 
	Dave Stevenson <dave.stevenson@...pberrypi.com>, Rob Clark <robdclark@...il.com>, 
	dri-devel@...ts.freedesktop.org, freedreno@...ts.freedesktop.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/2] drm/bridge-connector: reset the HDMI connector state

On Tue, 25 Jun 2024 at 01:28, Abhinav Kumar <quic_abhinavk@...cinc.com> wrote:
>
>
>
> On 6/22/2024 10:40 PM, Dmitry Baryshkov wrote:
> > On HDMI connectors which use drm_bridge_connector and DRM_BRIDGE_OP_HDMI
> > IGT chokes on the max_bpc property in several kms_properties tests due
> > to the the drm_bridge_connector failing to reset HDMI-related
> > properties.
> >
> > Call __drm_atomic_helper_connector_hdmi_reset() if there is a
> > the drm_bridge_connector has bridge_hdmi.
> >
> > Note, the __drm_atomic_helper_connector_hdmi_reset() is moved to
> > drm_atomic_state_helper.c because drm_bridge_connector.c can not depend
> > on DRM_DISPLAY_HDMI_STATE_HELPER. At the same time it is impossible to
> > call this function from HDMI bridges, there is is no function that
> > corresponds to the drm_connector_funcs::reset().
> >
> > Fixes: 6b4468b0c6ba ("drm/bridge-connector: implement glue code for HDMI connector")
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
> > ---
> >   drivers/gpu/drm/display/drm_hdmi_state_helper.c | 21 ---------------------
> >   drivers/gpu/drm/drm_atomic_state_helper.c       | 21 +++++++++++++++++++++
> >   drivers/gpu/drm/drm_bridge_connector.c          | 13 ++++++++++++-
> >   include/drm/display/drm_hdmi_state_helper.h     |  3 ---
> >   include/drm/drm_atomic_state_helper.h           |  2 ++
> >   5 files changed, 35 insertions(+), 25 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
> > index 2dab3ad8ce64..67f39857b0b4 100644
> > --- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
> > +++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
> > @@ -8,27 +8,6 @@
> >   #include <drm/display/drm_hdmi_helper.h>
> >   #include <drm/display/drm_hdmi_state_helper.h>
> >
> > -/**
> > - * __drm_atomic_helper_connector_hdmi_reset() - Initializes all HDMI @drm_connector_state resources
> > - * @connector: DRM connector
> > - * @new_conn_state: connector state to reset
> > - *
> > - * Initializes all HDMI resources from a @drm_connector_state without
> > - * actually allocating it. This is useful for HDMI drivers, in
> > - * combination with __drm_atomic_helper_connector_reset() or
> > - * drm_atomic_helper_connector_reset().
> > - */
> > -void __drm_atomic_helper_connector_hdmi_reset(struct drm_connector *connector,
> > -                                           struct drm_connector_state *new_conn_state)
> > -{
> > -     unsigned int max_bpc = connector->max_bpc;
> > -
> > -     new_conn_state->max_bpc = max_bpc;
> > -     new_conn_state->max_requested_bpc = max_bpc;
> > -     new_conn_state->hdmi.broadcast_rgb = DRM_HDMI_BROADCAST_RGB_AUTO;
> > -}
> > -EXPORT_SYMBOL(__drm_atomic_helper_connector_hdmi_reset);
> > -
> >   static const struct drm_display_mode *
> >   connector_state_get_mode(const struct drm_connector_state *conn_state)
> >   {
> > diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
> > index 519228eb1095..1518ada81b45 100644
> > --- a/drivers/gpu/drm/drm_atomic_state_helper.c
> > +++ b/drivers/gpu/drm/drm_atomic_state_helper.c
> > @@ -478,6 +478,27 @@ void drm_atomic_helper_connector_reset(struct drm_connector *connector)
> >   }
> >   EXPORT_SYMBOL(drm_atomic_helper_connector_reset);
> >
> > +/**
> > + * __drm_atomic_helper_connector_hdmi_reset() - Initializes all HDMI @drm_connector_state resources
> > + * @connector: DRM connector
> > + * @new_conn_state: connector state to reset
> > + *
> > + * Initializes all HDMI resources from a @drm_connector_state without
> > + * actually allocating it. This is useful for HDMI drivers, in
> > + * combination with __drm_atomic_helper_connector_reset() or
> > + * drm_atomic_helper_connector_reset().
> > + */
> > +void __drm_atomic_helper_connector_hdmi_reset(struct drm_connector *connector,
> > +                                           struct drm_connector_state *new_conn_state)
> > +{
> > +     unsigned int max_bpc = connector->max_bpc;
> > +
> > +     new_conn_state->max_bpc = max_bpc;
> > +     new_conn_state->max_requested_bpc = max_bpc;
>
> I understand this is just code propagation but do we need a max_bpc
> local variable?
>
> We can just do
>
> new_conn_state->max_bpc = connector->max_bpc;
> new_conn_state->max_requested_bpc = connector->max_bpc;

Possible implementation, but I was really just doing code move.

>
> But apart from that nit, this LGTM.
>
> Reviewed-by: Abhinav Kumar <quic_abhinavk@...cinc.com>



-- 
With best wishes
Dmitry