Re: [PATCH 1/2] drm/gma500: Add missing call to allow enabling vblank on psb/cdv

[Patrik Jakobsson]

On Wed, Nov 6, 2019 at 10:44 AM Paul Kocialkowski
<paul.kocialkowski@xxxxxxxxxxx> wrote:
>
> This adds a missing call to drm_crtc_vblank_on to the common DPMS helper
> (used by poulsbo and cedartrail), which is called in the CRTC enable path.
>
> With that call, it becomes possible to enable vblank when needed.
> It is already balanced by a drm_crtc_vblank_off call in the helper.
>
> Other platforms (oaktrail and medfield) use a dedicated DPMS helper that
> does not have the proper vblank on/off hooks. They are not added in this
> commit due to lack of hardware to test it with.
>
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx>

Don't think we ever found a need for having vblanks enabled... until
now. I'll have a look if something can be done for Oaktrail since I
have hw.

Reviewed-by: Patrik Jakobsson <patrik.r.jakobsson@xxxxxxxxx>

> ---
>  drivers/gpu/drm/gma500/gma_display.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/gma500/gma_display.c b/drivers/gpu/drm/gma500/gma_display.c
> index e20ccb5d10fd..bc07ae2a9a1d 100644
> --- a/drivers/gpu/drm/gma500/gma_display.c
> +++ b/drivers/gpu/drm/gma500/gma_display.c
> @@ -255,6 +255,8 @@ void gma_crtc_dpms(struct drm_crtc *crtc, int mode)
>                 /* Give the overlay scaler a chance to enable
>                  * if it's on this pipe */
>                 /* psb_intel_crtc_dpms_video(crtc, true); TODO */
> +
> +               drm_crtc_vblank_on(crtc);
>                 break;
>         case DRM_MODE_DPMS_OFF:
>                 if (!gma_crtc->active)
> --
> 2.23.0
>