On 5 August 2013 18:40, Kalle Valo <kvalo@xxxxxxxxxxxxxxxx> wrote: > Michal Kazior <michal.kazior@xxxxxxxxx> writes: > >> On 2 August 2013 09:58, Bartosz Markowski <bartosz.markowski@xxxxxxxxx> wrote: >>> Unify the PCI options location. >>> >>> By default the SoC PS option is disabled to boost the >>> performance and due to poor stability on early HW revisions. >>> In future we can remove the module parameter and turn on/off >>> the PS for given hardware. >>> >>> This change also makes the pci module parameter for SoC PS static. >>> >>> Signed-off-by: Bartosz Markowski <bartosz.markowski@xxxxxxxxx> >> >> Hmm.. I'm worried about pci wake/sleep locking: >> >> (a) pci_wake() (awake count =1) >> (a) do something >> Now, if pci_sleep() and pci_wake() happen simultaneously/are >> preempted splitting primitive operations to: >> (a) pci_sleep(): decrease awake count (=0) >> (b) pci_wake(): increase awake count (=1), iowrite, wait for awake, return >> (a) pci_sleep(): iowrite(). return >> The flow in (b) now thinks the device is awake, but it's not >> guaranteed to be anymore because it has been put to sleep by (a). > > Yeah, there's a race alright. I wonder if I have ever seen a proper use > of a atomic variable in a wireless driver :) > > But this doesn't prevent taking this patch as the race has existed since > the beginning, right? I don't have anything against it. I just noticed the race and thought it's good to point out the issue. Pozdrawiam / Best regards, Michał Kazior. -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
