[PATCH] drm/tilcdc: restore correct display mode and contents on pm resume

[Rob Clark]

On Mon, Mar 3, 2014 at 2:08 PM, Felipe Balbi <balbi at ti.com> wrote:
> From: Darren Etheridge <detheridge at ti.com>
>
> On resume the screen contents were not being restored properly.  Looking at
> other DRM drivers it seems a call to drm_helper_resume_force_mode() is needed
> in the resume handler to force restoration of the mode and framebuffer data.
>
> Signed-off-by: Darren Etheridge <detheridge at ti.com>

Reviewed-by: Rob Clark <robdclark at gmail.com>

> ---
>  drivers/gpu/drm/tilcdc/tilcdc_drv.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
> index 171a820..1a5ddfa 100644
> --- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
> +++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
> @@ -563,6 +563,13 @@ static int tilcdc_pm_resume(struct device *dev)
>                 if (registers[i].save && (priv->rev >= registers[i].rev))
>                         tilcdc_write(ddev, registers[i].reg, priv->saved_register[n++]);
>
> +       /*
> +        * if this call isn't here, the display is blank on return from
> +        * suspend.  With this call here the contents of the framebuffer
> +        * during suspend are restored correctly.
> +        */
> +       drm_helper_resume_force_mode(ddev);
> +
>         drm_kms_helper_poll_enable(ddev);
>
>         return 0;
> --
> 1.9.0
>