Messages in this thread | | | Date | Mon, 16 Feb 2015 12:23:43 +0000 | From | Mark Rutland <> | Subject | Re: [PATCH v4 3/5] irqchip: Add DT binding doc for the virtual irq demuxer chip |
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> > The "suspend" part is kind of a distraction to me here, because that really > > only is about sharing an IRQ with a timer and the "your interrupt handler > > may be called when the device is suspended" part is just a consequence of that. > > > > So IMO it's better to have "TIMER" in the names to avoid encouraging people to > > abuse this for other purposes not related to timers. > > Sorry to be late to the bike-shed party, but what about:
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> arch/arm/mach-omap2/mux.c: omap_hwmod_mux_handle_irq, IRQF_SHARED | IRQF_NO_SUSPEND, > arch/arm/mach-omap2/pm34xx.c: _prcm_int_handle_io, IRQF_SHARED | IRQF_NO_SUSPEND, "pm_io", > drivers/pinctrl/pinctrl-single.c: IRQF_SHARED | IRQF_NO_SUSPEND,
These are chained IRQ handlers. If any of these have a chained timer irq then the IRQF_NO_SUSPEND may be legitimate. I can't imagine why these would be shared, however.
It also looks like these abuse IRQF_NO_SUSPEND for wakeup interrupts.
> drivers/rtc/rtc-pl031.c: .irqflags = IRQF_SHARED | IRQF_NO_SUSPEND,
This looks to be an abuse and should use {enable,disable}_irq_wake.
However, we'd then need to handle mismatch with wakeup interrupts (which is effectively the same problem as sharing with a timer).
> drivers/mfd/ab8500-debugfs.c: IRQF_SHARED | IRQF_NO_SUSPEND, > drivers/mfd/ab8500-gpadc.c: IRQF_NO_SUSPEND | IRQF_SHARED, "ab8500-gpadc-sw", > drivers/mfd/ab8500-gpadc.c: IRQF_NO_SUSPEND | IRQF_SHARED, "ab8500-gpadc-hw", > drivers/power/ab8500_btemp.c: IRQF_SHARED | IRQF_NO_SUSPEND, > drivers/power/ab8500_charger.c: IRQF_SHARED | IRQF_NO_SUSPEND, > drivers/power/ab8500_fg.c: IRQF_SHARED | IRQF_NO_SUSPEND, > drivers/usb/phy/phy-ab8500-usb.c: IRQF_NO_SUSPEND | IRQF_SHARED, > drivers/usb/phy/phy-ab8500-usb.c: IRQF_NO_SUSPEND | IRQF_SHARED, > drivers/usb/phy/phy-ab8500-usb.c: IRQF_NO_SUSPEND | IRQF_SHARED,
All the *ab8500* look cargo-culted. There's other nonsense in these (e.g. mutex_lock in irq handlers...). I suspect these are not legitimate.
> drivers/watchdog/intel-mid_wdt.c: IRQF_SHARED | IRQF_NO_SUSPEND, "watchdog",
Watchdogs could be a legitimate case, but this driver relies on another timer and the timeout irq handler simply calls panic(), which seems a little extreme.
> Is there a single legitimate user in that list? If so, the TIMER name > might be misleading.
The watchdog case could be legitimate, and with drivers corrected to use {enable,disable}_irq_wake we'll need to handle mismatch for wakeup interrupts too.
Having separate flags for sharing with timers and sharing with wakeup sources seems redundant, and IRQF_SHARED_TIMER_OK would be misleading.
Thanks, Mark.
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