[Intel-gfx] [PATCH v3 3/3] drm: clean cached display info

[Daniel Vetter]

On Thu, Dec 22, 2016 at 10:21:25AM +0000, Jose Abreu wrote:
> Hi Shashank,
> 
> 
> On 21-12-2016 15:29, Shashank Sharma wrote:
> > This patch adds a small helper function, which clears the cached
> > information about a hot-pluggable display, from connector. On event
> > This will run on event of a hot-unplug, keeping the connector's display
> > info up-to-date, avoiding any errors due to invalid cached data.
> >
> > Cc: Jose Abreu <joabreu at synopsys.com>
> >
> > Suggested-by: Jose Abreu <joabreu at synopsys.com>
> > Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
> > ---
> >  drivers/gpu/drm/drm_probe_helper.c | 20 ++++++++++++++++++++
> >  1 file changed, 20 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
> > index 7cff91e..9e97b45 100644
> > --- a/drivers/gpu/drm/drm_probe_helper.c
> > +++ b/drivers/gpu/drm/drm_probe_helper.c
> > @@ -164,6 +164,18 @@ void drm_kms_helper_poll_enable_locked(struct drm_device *dev)
> >  }
> >  
> >  /**
> > + * drm_helper_clear_display_info - clean cached display information for
> > + * hot pluggable displays, on event of hot-unplug
> > + * @connector: connector under event
> > + */
> > +void drm_helper_clear_display_info(struct drm_connector *connector)
> > +{
> > +	struct drm_display_info *info = &connector->display_info;
> > +
> > +	memset(info, 0, sizeof(*info));
> > +}
> > +
> > +/**
> >   * drm_helper_probe_single_connector_modes - get complete set of display modes
> >   * @connector: connector to probe
> >   * @maxX: max width for modes
> > @@ -288,6 +300,14 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
> >  		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
> >  			connector->base.id, connector->name);
> >  		drm_mode_connector_update_edid_property(connector, NULL);
> > +
> > +		/*
> > +		 * Connector status change to disconnected, time to clean
> > +		 * cached display information
> > +		 */
> > +		if (connector->status == connector_status_disconnected)
> > +			drm_helper_clear_display_info(connector);
> > +
> 
> I don't know if this is the right place to do this because it is
> a helper and I don't know if it is used by all the drivers. We
> may need something more general that is always called when
> probing modes, or force drivers that don't use the helper to use
> the drm_helper_clear_display_info function. As I told you before,
> I'm new to dri-devel so we need more comments.

Seems reasonable to me, since afaik all drivers do use the probe helpers.
-Daniel

> 
> Best regards,
> Jose Miguel Abreu
> 
> >  		verbose_prune = false;
> >  		goto prune;
> >  	}
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch