On Thu, Nov 12, 2015 at 06:40:18PM +0200, Imre Deak wrote: > Atm, we assert that the device is not suspended until the point when the > HW is truly put to a suspended state. This is fine, but we can catch > more problems if we check the RPM refcount. After that one drops to zero > we shouldn't access the HW any more, although the actual suspend may be > delayed. Based on this change the assert_rpm_wakelock_held helper to > check the refcount instead of the device suspended state. > > After this change we need to annotate every place explicitly in the code > where we expect that the HW is in D0 state. Atm in the driver load > function the D0 state is implicit until we enable runtime PM, but for > these asserts to work we need to add explicit RPM get/put calls, so fix > this up. > > Another place where the D0 state is implicit even with a 0 RPM refcount > is the system and runtime sudpend/resume handlers and the hangcheck > work. In the former case the susend/resume handlers themselves determine > at which exact spot the HW is truly on/off and in the latter case the > work will be flushed in the suspend handler before turning off the HW. > We regard these cases special and disable the RPM asserts for their > duration. In the hangcheck work we can nevertheless check that the > device is not suspended. Fix up these things. > > These explicit annotations also have the positive side effect of > documenting our assumptions better. > > This caught additional WARNs from the atomic modeset path, those should > be fixed separately. > > v2: > - remove the redundant HAS_RUNTIME_PM check (moved to patch 1) (Ville) > v3: > - use a new dedicated RPM wakelock refcount to also catch cases where > our own RPM get/put functions were not called (Chris) > - assert also that the new RPM wakelock refcount is 0 in the RPM > suspend handler (Chris) > - change the assert error message to be more meaningful (Chris) > - prevent false assert errors and check that the RPM wakelock is 0 in > the RPM resume handler too > - prevent false assert errors in the hangcheck work too > - add a device not suspended assert check to the hangcheck work > > Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx> Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
