"Rafael J. Wysocki" <rjw@xxxxxxx> writes: > On Friday, August 05, 2011, Kevin Hilman wrote: >> "Rafael J. Wysocki" <rjw@xxxxxxx> writes: >> >> > On Friday, July 22, 2011, Kevin Hilman wrote: >> >> Currently the use of pm_runtime_put_sync() is not safe from >> >> interrupts-disabled context because rpm_idle() will release the >> >> spinlock and enable interrupts for the idle callbacks. This enables >> >> interrupts during a time where interrupts were expected to be >> >> disabled, and can have strange side effects on drivers that expected >> >> interrupts to be disabled. >> >> >> >> This is not a bug since the documentation clearly states that only >> >> _put_sync_suspend() is safe in IRQ-safe mode. >> >> >> >> However, pm_runtime_put_sync() could be made safe when in IRQ-safe >> >> mode by releasing the spinlock but not re-enabling interrupts, which >> >> is what this patch aims to do. >> >> >> >> Problem was found when using some buggy drivers that set >> >> pm_runtime_irq_safe() and used _put_sync() in interrupts-disabled >> >> context. >> >> >> >> The offending drivers have been fixed to use _put_sync_suspend(), >> >> But this patch is an RFC to see if it might make sense to allow >> >> using _put_sync() from interrupts-disabled context. >> > >> > OK, I'm going to take this for 3.2. >> >> Rafael, >> >> Since you're planning to merge this, maybe we should consider merging >> this as a fix for v3.1, and possibly even for v3.0 stable. That way, >> any current drivers using irq_safe and the normal _put_sync() will not >> have this problem. > > I think I can push it for 3.1, but I don't think it's stable material. > OK, fair enough. Kevin _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
