Re: [Intel-gfx] [PATCH] drm/i915: Disable D3Cold in s2idle and runtime pm

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Mon, Nov 15, 2021 at 02:20:36PM -0500, Rodrigo Vivi wrote:
> On Mon, Nov 15, 2021 at 09:10:54PM +0530, Tilak Tangudu wrote:
> > s2idle and runtime pm puts the pci gfx device in D3Hot, ACPI runtime
> > monitors the pci tree,if it sees complete tree as D3Hot,it transitions
> > the device to D3Cold.But i915 do not have D3Cold support in S2idle or in
> > runtime pm. so disabling D3cold in above flows and its FIXME.
> > 
> > Added pci D3Cold enable/disable in s2idle and runtime suspend/resume
> > flows.
> > 
> > Signed-off-by: Tilak Tangudu <tilak.tangudu@intel.com>
> 
> Just for the clear record, I always preferred the unconditional disallow
> of d3cold, but it looks some internal experiments for s3/s4 failed with that
> and this approach here was the safest one, so let's move with this and
> prevent the d3cold for now and then allow the runtime_pm autosuspend
> enabled by default everywhere.
> 
> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

and pushed, thanks for the patch.

> 
> > ---
> >  drivers/gpu/drm/i915/i915_drv.c | 19 +++++++++++++++++++
> >  1 file changed, 19 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> > index 46bf3315f616..af6868f12ef0 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.c
> > +++ b/drivers/gpu/drm/i915/i915_drv.c
> > @@ -1194,6 +1194,14 @@ static int i915_drm_suspend_late(struct drm_device *dev, bool hibernation)
> >  		goto out;
> >  	}
> >  
> > +	/*
> > +	 * FIXME: Temporary hammer to avoid freezing the machine on our DGFX
> > +	 * This should be totally removed when we handle the pci states properly
> > +	 * on runtime PM and on s2idle cases.
> > +	 */
> > +	if (suspend_to_idle(dev_priv))
> > +		pci_d3cold_disable(pdev);
> > +
> >  	pci_disable_device(pdev);
> >  	/*
> >  	 * During hibernation on some platforms the BIOS may try to access
> > @@ -1357,6 +1365,8 @@ static int i915_drm_resume_early(struct drm_device *dev)
> >  
> >  	pci_set_master(pdev);
> >  
> > +	pci_d3cold_enable(pdev);
> > +
> >  	disable_rpm_wakeref_asserts(&dev_priv->runtime_pm);
> >  
> >  	ret = vlv_resume_prepare(dev_priv, false);
> > @@ -1533,6 +1543,7 @@ static int intel_runtime_suspend(struct device *kdev)
> >  {
> >  	struct drm_i915_private *dev_priv = kdev_to_i915(kdev);
> >  	struct intel_runtime_pm *rpm = &dev_priv->runtime_pm;
> > +	struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
> >  	int ret;
> >  
> >  	if (drm_WARN_ON_ONCE(&dev_priv->drm, !HAS_RUNTIME_PM(dev_priv)))
> > @@ -1578,6 +1589,12 @@ static int intel_runtime_suspend(struct device *kdev)
> >  		drm_err(&dev_priv->drm,
> >  			"Unclaimed access detected prior to suspending\n");
> >  
> > +	/*
> > +	 * FIXME: Temporary hammer to avoid freezing the machine on our DGFX
> > +	 * This should be totally removed when we handle the pci states properly
> > +	 * on runtime PM and on s2idle cases.
> > +	 */
> > +	pci_d3cold_disable(pdev);
> >  	rpm->suspended = true;
> >  
> >  	/*
> > @@ -1616,6 +1633,7 @@ static int intel_runtime_resume(struct device *kdev)
> >  {
> >  	struct drm_i915_private *dev_priv = kdev_to_i915(kdev);
> >  	struct intel_runtime_pm *rpm = &dev_priv->runtime_pm;
> > +	struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
> >  	int ret;
> >  
> >  	if (drm_WARN_ON_ONCE(&dev_priv->drm, !HAS_RUNTIME_PM(dev_priv)))
> > @@ -1628,6 +1646,7 @@ static int intel_runtime_resume(struct device *kdev)
> >  
> >  	intel_opregion_notify_adapter(dev_priv, PCI_D0);
> >  	rpm->suspended = false;
> > +	pci_d3cold_enable(pdev);
> >  	if (intel_uncore_unclaimed_mmio(&dev_priv->uncore))
> >  		drm_dbg(&dev_priv->drm,
> >  			"Unclaimed access during suspend, bios?\n");
> > -- 
> > 2.25.1
> >