[PATCH] drm: Fire off KMS hotplug events if probe detect says the connector is connected

[Mun, Gwan-gyeong]

On Thu, 2019-04-18 at 10:28 +0200, Daniel Vetter wrote:
> On Thu, Apr 18, 2019 at 11:09:29AM +0300, Gwan-gyeong Mun wrote:
> > The hotplug detection routine of drm_helper_hpd_irq_event() can
> > detect
> > changing of status of connector, but it can not detect changing of
> > properties of the connector.
> > e.g. changing of edid while suspend/resume, changing of dp lanes in
> > dp aux.
> > 
> > Following scenario explains one of them; A detection of changing of
> > edid.
> > 
> >  1) plug display device to a connector
> >  2) system suspend
> >  3) unplug 1)'s display device and plug the other display device to
> > a
> >     connector
> >  4) system resume
> > 
> > To solve explained cases, It fires off KMS hotplug events if
> > drm_helper_probe_detect() says the connector is connected.
> > 
> > Testcase: igt/kms_chamelium/hdmi-edid-change-during-hibernate
> > Testcase: igt/kms_chamelium/hdmi-edid-change-during-suspend
> > Testcase: igt/kms_chamelium/dp-edid-change-during-hibernate
> > Testcase: igt/kms_chamelium/dp-edid-change-during-suspend
> > 
> > Suggested-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> 
> This isn't at all what I suggested.
> -Daniel
Because the code modification was followed by your comments, so I added
suggested-by line. I will remove this line and will resend it.
Br,
G.G.
> 
> > Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun at intel.com>
> > Link: 
> > https://lists.freedesktop.org/archives/dri-devel/2019-April/214572.html
> > ---
> >  drivers/gpu/drm/drm_probe_helper.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_probe_helper.c
> > b/drivers/gpu/drm/drm_probe_helper.c
> > index 6fd08e04b323..081a849104f2 100644
> > --- a/drivers/gpu/drm/drm_probe_helper.c
> > +++ b/drivers/gpu/drm/drm_probe_helper.c
> > @@ -780,7 +780,8 @@ bool drm_helper_hpd_irq_event(struct drm_device
> > *dev)
> >  			      connector->name,
> >  			      drm_get_connector_status_name(old_status)
> > ,
> >  			      drm_get_connector_status_name(connector-
> > >status));
> > -		if (old_status != connector->status)
> > +		if (old_status != connector->status ||
> > +		    connector->status == connector_status_connected)
> >  			changed = true;
> >  	}
> >  	drm_connector_list_iter_end(&conn_iter);
> > -- 
> > 2.21.0
> >