Hi Maxime, > -----Original Message----- > From: Maxime Ripard <mripard@xxxxxxxxxx> > Sent: Monday, July 8, 2024 9:54 AM > Subject: Re: [PATCH] drm: renesas: shmobile: shmo_drm_crtc: Fix PM imbalance if RPM_ACTIVE is true > > Hi, > > 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> > > --- > > drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c > > b/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c > > index 2e2f37b9d0a4..42a5d6876bec 100644 > > --- 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. Cheers, Biju
