On Wed, May 20, 2020 at 12:45:56PM -0400, stern@xxxxxxxxxxxxxxxxxxx wrote: > On Wed, May 20, 2020 at 03:42:17PM +0000, Sverdlin, Alexander (Nokia - DE/Ulm) wrote: > > Hello Dinghao, > > > > On Wed, 2020-05-20 at 21:29 +0800, Dinghao Liu wrote: > > > pm_runtime_get_sync() increments the runtime PM usage counter even > > > the call returns an error code. Thus a pairing decrement is needed > > > on the error handling path to keep the counter balanced. > > > > I believe, this is the wrong place for such kind of fix. > > pm_runtime_get_sync() has obviously a broken semantics with regards to > > your observation but no other driver does what you propose. > > Look again. For example, see what usb_autoresume_device() in > drivers/usb/core/driver.c does. However, there seems to be some disagreement as to what to do when pm_runtime_get_sync fails. Your driver chooses to call put_sync while others prefer pm_runtime_put_noidle (e.g., see drivers/base/power/runtime.c). This API does seem to be in a bit of a mess. Cheers, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
