Hi Biju, On Mon, Jul 8, 2024 at 11:00 AM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote: > > From: Maxime Ripard <mripard@xxxxxxxxxx> > > On Mon, Jul 08, 2024 at 09:27:09AM GMT, Biju Das wrote: > > > The pm_runtime_resume_and_get() returns 1 if RPM is active, in this > > > case it won't call a put. This will result in PM imbalance as it treat > > > this as an error and propagate this to caller and the caller never > > > calls corresponding put(). Fix this issue by checking error condition > > > only. > > > > > > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx> > > > --- a/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c > > > +++ b/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c > > > @@ -208,7 +208,7 @@ static void shmob_drm_crtc_atomic_enable(struct drm_crtc *crtc, > > > int ret; > > > > > > ret = pm_runtime_resume_and_get(dev); > > > - if (ret) > > > + if (ret < 0) > > > return; > > > > The documentation of pm_runtime_resume_and_get says that: > > > > Resume @dev synchronously and if that is successful, increment its > > runtime PM usage counter. Return 0 if the runtime PM usage counter of > > @dev has been incremented or a negative error code otherwise. > > > > So it looks like it can't return 1, ever. Are you sure you're not confusing pm_runtime_resume_and_get > > with pm_runtime_get? > > It should be ret < 0 as ret = 1 corresponds to RPM_ACTIVE and the API does not call put() when ret = 1; see [1] and [2] > > [1] https://elixir.bootlin.com/linux/v6.10-rc6/source/drivers/base/power/runtime.c#L778 > > [2] https://elixir.bootlin.com/linux/v6.10-rc6/source/include/linux/pm_runtime.h#L431 > > Am I miss anything? Please let me know. Thanks for your patch, but the code for pm_runtime_resume_and_get() seems to disagree? https://elixir.bootlin.com/linux/latest/source/include/linux/pm_runtime.h#L436 Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
