On Tue, Aug 23, 2022 at 03:56:56PM +0300, Golani, Mitulkumar Ajitkumar wrote: > > Hi Imre, > > > > > On Fri, Aug 12, 2022 at 10:17:24AM +0530, Mitul Golani wrote: > > > > While executing i915_selftest, wakeref imbalance warning is seen > > > > with i915_selftest failure. > > > > > > > > When device is already suspended, wakeref is acquired by > > > > disable_rpm_wakeref_asserts and rpm ownership is transferred back to > > > > core. During this case wakeref_count will not be zero. > > > > Once driver is unregistered, this wakeref is released with > > > > enable_rpm_wakeref_asserts and balancing wakeref_count acquired by > > > > driver. > > > > > > > > This patch will fix the warning callstack by adding check if device > > > > is already suspended and rpm ownership transfer is going on. > > > > > > > > Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@xxxxxxxxx> > > > > --- > > > > drivers/gpu/drm/i915/i915_driver.c | 8 +++++++- > > > > 1 file changed, 7 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/gpu/drm/i915/i915_driver.c > > > > b/drivers/gpu/drm/i915/i915_driver.c > > > > index deb8a8b76965..6530a8680cfd 100644 > > > > --- a/drivers/gpu/drm/i915/i915_driver.c > > > > +++ b/drivers/gpu/drm/i915/i915_driver.c > > > > @@ -1670,7 +1670,13 @@ static int intel_runtime_resume(struct device > > > > *kdev) > > > > > > > > drm_dbg(&dev_priv->drm, "Resuming device\n"); > > > > > > > > - drm_WARN_ON_ONCE(&dev_priv->drm, atomic_read(&rpm- > > > >wakeref_count)); > > > > + /* > > > > + * When device is already suspended, Wakeref is acquired by > > > disable_rpm_wakeref_asserts > > > > + * and rpm ownership is transferred back to core. During this case > > > wakeref_count will > > > > + * not be zero. Once driver is unregistered, this wakeref is > > > > +released > > > with > > > > + * enable_rpm_wakeref_asserts and balancing wakeref_count > > > acquired by driver. > > > > + */ > > > > + drm_WARN_ON_ONCE(&dev_priv->drm, atomic_read(&rpm- > > > >wakeref_count) && > > > > +!rpm->suspended); > > > > > > I can't see how disable/enable_rpm_wakeref_asserts() can lead to this > > > WARN. They are always called in pairs both in intel_runtime_suspend() > > > and intel_runtime_resume(), leaving rpm->wakeref_count unchanged. > > > > > > The root cause is probably somewhere else, incrementing > > > rpm->wakeref_count without runtime resuming the device. > > > > > > The WARN() condition is corret, we shouldn't get here with a non-zero > > > wakeref_count. rpm->suspended - set in intel_runtime_suspend() and > > > cleared in intel_runtime_resume() - should be always false here, so > > > the above change would just disable the WARN in all cases. > > > > > Yes, in case of DG2, after device is suspended, i915_driver_remove > > is being called. Here driver is taking wakeref with > > disable_rpm_wakeref_asserts when device was not resumed. > > > > As per logs, > > [ 395.872971] i915 0000:03:00.0: [drm:intel_runtime_suspend [i915]] > > Suspending device ... > > [ 403.553235] i915_driver_remove: START wakeref=0 [ 403.553288] > > i915_driver_remove: before unregister i915 wakeref=65537 (Wakeref Taken) > > [ 403.566086] i915 0000:03:00.0: [drm:intel_runtime_resume [i915]] > > Resuming device (Later Resuming Device) > > > > Pushed new change with : > > https://patchwork.freedesktop.org/series/107211/#rev5 > > > Also when compared DG2 logs with ADLP working logs, > Already 1 wakeref was taken by DMC firmware(i915/adlp_dmc_ver2_16.bin (v2.16)), in-case of DG2 looks to be missing. > To support other targets and to prevent consecutive resuming device added following check, > if (i915->runtime_pm.suspended && !atomic_read(&i915->runtime_pm.wakeref_count)) > > ADLP Logs: > --------------- > [ 99.502434] i915_driver_probe: START wakeref=0 > [ 713.979074] i915 0000:00:02.0: [drm] Finished loading DMC firmware i915/adlp_dmc_ver2_16.bin (v2.16) > [ 102.455766] i915_driver_probe: END wakeref=65538 > ... > [ 103.448570] i915_driver_remove: START wakeref=65537 > [ 103.448587] i915_driver_remove: before unregister i915 wakeref=131074 -> (disable_rpm_wakeref_assert) > [ 103.585886] i915_driver_remove: END wakeref=0 > > DG2 Logs: > ------------- > [ 1271.704314] i915_driver_probe: START wakeref=0 > [ 383.050984] i915 0000:03:00.0: [drm] Finished loading DMC firmware i915/dg2_dmc_ver2_07.bin (v2.7) > [ 1272.021133] i915_driver_probe: END wakeref=1 > ... > [ 395.883531] i915 0000:03:00.0: [drm:intel_runtime_suspend [i915]] Device suspended > ... > [ 1291.450841] i915_driver_remove: START wakeref=0 > [ 1291.450877] i915_driver_remove: before unregister i915 wakeref=65537 -> (disable_rpm_wakeref_assert) > [ 1291.603281] i915_driver_remove: END wakeref=0 Still not sure what's going. Both i915_pci_probe() and i915_pci_remove()->i915_driver_remove() is called with a runtime PM reference - taken at local_pci_probe() and pci_device_remove() - and so the device should be runtime resumed at those points. > > > > disable_rpm_wakeref_asserts(rpm); > > > > > > > > intel_opregion_notify_adapter(dev_priv, PCI_D0); > > > > -- > > > > 2.25.1 > > > >
