[Intel-gfx] [PATCH 01/16] drm/i915: vlv: fix gunit HW state corruption during S4 suspend

[Sagar Arun Kamble]

>From DPM documentation, thaw_early should undo actions by freeze_late.
Can we move following snippet from thaw_early to thaw to comply with
this?

	intel_uncore_early_sanitize(dev, true);
        intel_uncore_sanitize(dev);
        intel_power_domains_init_hw(dev_priv);

On Wed, 2014-09-10 at 18:16 +0300, Imre Deak wrote:
> During S4 freeze we don't call intel_suspend_complete(), which would
> save the gunit HW state, but during S4 thaw/restore events we call
> intel_resume_prepare() which restores it, thus ending up in a corrupted
> HW state.
> 
> Fix this by calling intel_suspend_complete() from the corresponding
> freeze_late event handler.
> 
> The issue was introduced in
> commit 016970beb05da6285c2f3ed2bee1c676cb75972e
> Author: Sagar Kamble <sagar.a.kamble at intel.com>
> Date:   Wed Aug 13 23:07:06 2014 +0530
> 
> CC: Sagar Kamble <sagar.a.kamble at intel.com>
> Signed-off-by: Imre Deak <imre.deak at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index b8bd008..2365875 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -987,6 +987,15 @@ static int i915_pm_freeze(struct device *dev)
>  	return i915_drm_freeze(drm_dev);
>  }
>  
> +static int i915_pm_freeze_late(struct device *dev)
> +{
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +	struct drm_device *drm_dev = pci_get_drvdata(pdev);
> +	struct drm_i915_private *dev_priv = drm_dev->dev_private;
> +
> +	return intel_suspend_complete(dev_priv);
> +}
> +
>  static int i915_pm_thaw_early(struct device *dev)
>  {
>  	struct pci_dev *pdev = to_pci_dev(dev);
> @@ -1571,6 +1580,7 @@ static const struct dev_pm_ops i915_pm_ops = {
>  	.resume_early = i915_pm_resume_early,
>  	.resume = i915_pm_resume,
>  	.freeze = i915_pm_freeze,
> +	.freeze_late = i915_pm_freeze_late,
>  	.thaw_early = i915_pm_thaw_early,
>  	.thaw = i915_pm_thaw,
>  	.poweroff = i915_pm_poweroff,