[Intel-gfx] [PATCH 3/5] drm/i915: Update CRTC state if connector link status property changed

[Maarten Lankhorst]

Op 18-11-16 om 08:13 schreef Manasi Navare:
> CRTC state connector_changed needs to be set to true
> if connector link status property has changed. This will tell the
> driver to do a complete modeset due to change in connector property.
>
> Acked-by: Harry Wentland <harry.wentland at amd.com>
> Acked-by: Tony Cheng <tony.cheng at amd.com>
> Cc: dri-devel at lists.freedesktop.org
> Cc: Jani Nikula <jani.nikula at linux.intel.com>
> Cc: Daniel Vetter <daniel.vetter at intel.com>
> Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
> Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
> ---
>  drivers/gpu/drm/drm_atomic_helper.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index 0b16587..2125fd1 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -519,6 +519,13 @@ static int handle_conflicting_encoders(struct drm_atomic_state *state,
>  					       connector_state);
>  		if (ret)
>  			return ret;
> +
> +		if (connector->state->crtc) {
> +			crtc_state = drm_atomic_get_existing_crtc_state(state,
> +									connector->state->crtc);
> +			if (connector->link_status == DRM_MODE_LINK_STATUS_BAD)
> +				crtc_state->connectors_changed = true;
> +		}
>  	}
>  
>  	/*

This will cause ordinary atomic commits that happen to change connector flags to potentially fail with -EINVAL if ALLOW_MODESET is not set.
For this reason I'm not sure this flag should be set automatically by the kernel. Could we add add a retrain link property instead, that
always return 0 when queried, but writing a 1 causing connectors_changed to be set on bad link status?

~Maarten