Messages in this thread | | | Date | Tue, 6 Apr 2021 13:50:03 +0200 | From | Thierry Reding <> | Subject | Re: [PATCH 5.10 079/126] drm/tegra: sor: Grab runtime PM reference across reset |
| |
On Mon, Apr 05, 2021 at 05:42:21PM +0200, Pavel Machek wrote: > Hi! > > > However, these functions alone don't provide any guarantees at the > > system level. Drivers need to ensure that the only a single consumer has > > access to the reset at the same time. In order for the SOR to be able to > > exclusively access its reset, it must therefore ensure that the SOR > > power domain is not powered off by holding on to a runtime PM reference > > to that power domain across the reset assert/deassert operation. > > Yeah, but it should not leak the PM reference in the error handling.
True. However the only reason why the code could realistically fail between pm_runtime_resume_and_get() and pm_runtime_put() is if we did not take the runtime PM reference (which would cause the call to reset_control_acquire() to fail).
So the chances of this actually leaking are practically zero, so I didn't want to bloat this bugfix with what's essentially dead code. I can queue up your fix below for v5.14, though, since it's obviously more correct from a theoretical point of view.
Thierry [unhandled content-type:application/pgp-signature] | |