drm/i915: fix RPS on runtime suspend

With this patch, the RPS sequence for runtime suspend/resume is
exactly like the sequence for S3 suspend/resume:
 - flush_delayed_work(&dev_priv->rps.delayed_resume_work)
 - intel_runtime_pm_disable_interrupts()
 - intel_suspend_gt_powersave()
   (suspended)
 - intel_runtime_pm_enable_interrupts()
 - intel_enable_gt_powersave()

With this, we get rid of WARNs that are currently intermittently
triggered by the system-suspend-execbuf subtest of runtime PM. Notice
that these WARNs could also be triggered in other ways that involved
doing lots of RPM suspend/resume cycles just after a system S3 resume.

Testcase: igt/pm_rpm/system-suspend-execbuf
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reference: https://bugs.freedesktop.org/show_bug.cgi?id=82939
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 0c7cf480e85468e6e74f4009ed2757fd4fe47ea2..2404b2baa01ed74f8974ee36195a507406eab050 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1395,13 +1395,9 @@ static int intel_runtime_suspend(struct device *device)
        i915_gem_release_all_mmaps(dev_priv);
        mutex_unlock(&dev->struct_mutex);
 
-       /*
-        * rps.work can't be rearmed here, since we get here only after making
-        * sure the GPU is idle and the RPS freq is set to the minimum. See
-        * intel_mark_idle().
-        */
-       cancel_work_sync(&dev_priv->rps.work);
+       flush_delayed_work(&dev_priv->rps.delayed_resume_work);
        intel_runtime_pm_disable_interrupts(dev_priv);
+       intel_suspend_gt_powersave(dev);
 
        ret = intel_suspend_complete(dev_priv);
        if (ret) {
@@ -1473,7 +1469,7 @@ static int intel_runtime_resume(struct device *device)
        gen6_update_ring_freq(dev);
 
        intel_runtime_pm_enable_interrupts(dev_priv);
-       intel_reset_gt_powersave(dev);
+       intel_enable_gt_powersave(dev);
 
        if (ret)
                DRM_ERROR("Runtime resume failed, disabling it (%d)\n", ret);