On Wed, 2 Sep 2026 16:42:12 +0100 Adrián Larumbe <[email protected]> wrote:
> On 01.09.2026 15:18, Boris Brezillon wrote: > > On Fri, 28 Aug 2026 21:56:49 +0100 > > Adrián Larumbe <[email protected]> wrote: > > > > > During device probe(), failure to do a PM get() will leave the usage_count > > > set to 0, which is the value assigned at device creation time. That means > > > when the autosuspend delay expires, runtime suspend callback won't be > > > invoked, so the device will remain powered on forever. > > > > > > On top of that, failure to call PM put() during device unplug means > > > Panfrost device's PM usage_count increases monotonically for every new > > > module reload. > > > > > > The combined outcome of both of the above was that devfreq OPP transition > > > notifications would be printed all the time, even when no jobs are being > > > submitted. This quickly fills the kernel ring buffer with junk. > > > > > > To fix the above: > > > - Manually adjust the PM refcnt at device probe and removal time. > > > - Ensure pm_runtime_dont_use_autosuspend is called in the wind-down path. > > > - Call pm_runtime_put_autosuspend() when device is ready to accept jobs > > > > > > Signed-off-by: Adrián Larumbe <[email protected]> > > > Fixes: 635430797d3f ("drm/panfrost: Rework runtime PM initialization") > > > Fixes: 876b15d2c88d ("drm/panfrost: Fix module unload") > > > > Because of how things are currently ordered, this won't be backportable > > without patch 2, which doesn't have a Fixes tag, so, either we put the > > fix first, and then we move code, or we make it a single commit. > > I think I mentioned it in a previous reply. Maybe it's best to fix the > outstanding issues first > and then moving code into panfrost_{init|fini}(). I agree it'd be simpler to do that.
