[Intel-gfx] [PATCH] drm/i915: Force full PSR setup during crtc enable.

[Daniel Vetter]

On Tue, Jun 10, 2014 at 03:49:57AM -0700, Rodrigo Vivi wrote:
> Some registers set during setup might not be persistent after suspend/resume,
> and also on crtc off/on cycles.
> 
> This was causing bugs for some people that was unable to get PSR entry state
> after suspend/resume cycle.
> 
> v2: Adding some comments and better commit message explaining why this is
> needed. (by Paulo)
> v3: Moving psr.setup_done reset to crtc_enable because same issues might apply
> also on crtc off/on cycle. (by Daniel)
> 
> Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Joe Konno <joe.konno at intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index b5cbb28..077ab0e 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -3938,6 +3938,10 @@ static void intel_crtc_enable_planes(struct drm_crtc *crtc)
>  
>  	mutex_lock(&dev->struct_mutex);
>  	intel_update_fbc(dev);
> +	/* Forcing a full init sequence here to make sure all
> +	* registers are properly set. Some might not be persistent after
> +	* crtc on/off cycle. */
> +	dev_priv->psr.setup_done = false;
>  	intel_edp_psr_update(dev);

I think splitting edp_psr_update into a setup and an update function would
be cleaner. We kinda should have the same for fbc I think. This should
also help with the locking since at least for fbc the setup and the update
don't really need to do the same tasks.

For now I think you can just add a bool do_setup to edp_psr_update and
drop the dev_priv->psr.setup_done boolean instead.
-Daniel

>  	mutex_unlock(&dev->struct_mutex);
>  }
> -- 
> 1.9.3
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch