Messages in this thread | | | Date | Tue, 11 Jul 2017 09:34:34 -0700 | From | Tony Lindgren <> | Subject | Re: [GIT pull] irq updates for 4.13 |
| |
* Thomas Gleixner <tglx@linutronix.de> [170711 09:20]: > On Tue, 11 Jul 2017, Linus Torvalds wrote: > > > On Tue, Jul 11, 2017 at 7:41 AM, Thomas Gleixner <tglx@linutronix.de> wrote: > > > > > > Ah. Now that makes sense. > > > > > > Unpatched the ordering is: > > > > > > chip_bus_lock(desc); > > > irq_request_resources(desc); > > > > I *looked* at that ordering and then went "Naah, that makes no sense". > > > > But if that's the only issue, how about we just re-order those things > > - we still don't need to move the irq_request_resources() into the > > spinlock, we just move it to below the chip_bus_lock(). > > > > IOW, something like the (COMPLETELY UNTEESTED!) attached patch. > > > > This assumes that the chip_bus_lock() thing is still ok for the RT > > case, but it looks like it might be: the only other one I looked at > > (apart from the gpio-omap one) used a mutex. > > I looked through all of them and the only special case is gpio-omap. > > What I do not understand here is that we have already power management > around all of that. > > irq_chip_pm_get(&desc->irq_data); > ... > chip_bus_lock(desc); > ... > chip_bus_unlock_sync(desc); > ... > irq_chip_pm_put(&desc->irq_data); > > So why is that not sufficient and needs extra magic in that GPIO driver?
Yeah it seems we should eventually be able to use irq_chip_pm_get() like Grygorii just explained.
But aren't we currently calling chip functions with irq_request_resources() outside the chip_bus_lock() too in addition to the gpio-omap runtime PM issue? It seems that the patch from Linus fixes that, no?
Regards,
Tony
| |