[Intel-gfx] [PATCH] drm/i915: don't enable autosuspend on platforms without RPM support

[Imre Deak]

On to, 2015-12-17 at 17:19 +0000, Chris Wilson wrote:
> On Thu, Dec 17, 2015 at 07:04:33PM +0200, Imre Deak wrote:
> > Since
> > 
> > commit 357597e51dd1aa3cf764d322abf89217e3dcd7bb
> > Author: Imre Deak <imre.deak at intel.com>
> > Date:   Tue Nov 10 06:12:22 2015 +0200
> > 
> >     drm/i915: remove HAS_RUNTIME_PM check from RPM get/put/assert
> > helpers
> > 
> > this file is writeable also on platforms without RPM support, but
> 
> Which file?

sysfs power/autosuspend_delay_ms is only writeable by userspace if we
call pm_runtime_use_autosuspend().

> 
> > userspace (at least IGT) depends on this file being unchangable to
> > determine whether the device supports autosuspend. So restore the
> > old
> > behavior.
> > 
> > This gets rid of igt/pm_rpm failures on old platforms without RPM
> > support, where the test should be skipped.
> > 
> > Testcase: igt/pm_rpm/basic-rte
> > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_runtime_pm.c | 13 ++++++++-----
> >  1 file changed, 8 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c
> > b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > index a0b9eaf..ddbdbff 100644
> > --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > @@ -2309,18 +2309,21 @@ void intel_runtime_pm_enable(struct
> > drm_i915_private *dev_priv)
> >  	struct drm_device *dev = dev_priv->dev;
> >  	struct device *device = &dev->pdev->dev;
> >  
> > +	pm_runtime_set_autosuspend_delay(device, 10000); /* 10s */
> > +	pm_runtime_mark_last_busy(device);
> > +
> >  	/*
> >  	 * Take a permanent reference to disable the RPM
> > functionality and drop
> >  	 * it only when unloading the driver. Use the low level
> > get/put helpers,
> >  	 * so the driver's own RPM reference tracking asserts also
> > work on
> >  	 * platforms without RPM support.
> >  	 */
> > -	if (!HAS_RUNTIME_PM(dev))
> > +	if (!HAS_RUNTIME_PM(dev)) {
> > +		pm_runtime_dont_use_autosuspend(device);
> >  		pm_runtime_get_sync(device);
> > -
> > -	pm_runtime_set_autosuspend_delay(device, 10000); /* 10s */
> > -	pm_runtime_mark_last_busy(device);
> > -	pm_runtime_use_autosuspend(device);
> > +	} else {
> > +		pm_runtime_use_autosuspend(device);
> > +	}
> 
> This seems to make sense to me.
> -Chris
>