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

[Daniel Vetter]

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

> 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
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch