Commit cab303be91dc47942bc25de33dc1140123540800 [1] introduced a WARN_ON test which triggers a WARNING backtrace on at91 platforms. While this WARN_ON is absolutely necessary to warn users that they should not mix request with and without IRQF_NO_SUSPEND flags on shared IRQs, there is no easy way to solve this issue on at91 platforms. The main reason is that the init timer is often using a shared irq line and thus request this irq with IRQF_NO_SUSPEND flag set, while other peripherals request the same irq line without this flag. We could deal with that by identifying whether a given peripheral is connected to the init timer shared irq line and add the IRQF_NO_SUSPEND in this case, but this implies adding the logic in all peripheral drivers that could be connected to this shared irq. This series takes the reverse approach: force IRQ users to specify that they take care of disabling peripheral interrupts and that IRQ core can safely leave the handler in a suspended state without having to bother about spurious interrupts. This is done by mean of a new IRQF_SUSPEND_NOACTION flag which tells the core to move the action handler to a suspended list, thus preventing its execution when we are in suspend mode. Of course, specifying the IRQF_SUSPEND_NOACTION flag implies taking care of masking/unmasking the peripheral interrupts in the suspend/resume implementation. The WARN_ON is kept, but now it is only triggered when (no_suspend_depth + suspend_noaction_depth) and nr_actions are unbalanced. The first patch introduces the IRQF_SUSPEND_NOACTION logic, while other patches modify existing at91 drivers to specify this flag (and implement suspend/resume if needed). Best Regards, Boris [1]https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/kernel/irq/pm.c?id=cab303be91dc47942bc25de33dc1140123540800 Boris Brezillon (5): genirq: Support mixing IRQF_NO_SUSPEND/IRQF_SUSPEND on shared irqs clk: at91: implement suspend/resume for the PMC irqchip watchdog: at91sam9: request the irq with IRQF_NO_SUSPEND rtc: at91: request IRQs with IRQF_SUSPEND_NOACTION tty: serial: atmel: request IRQ with IRQF_SUSPEND_NOACTION drivers/clk/at91/pmc.c | 20 ++++++++++- drivers/clk/at91/pmc.h | 1 + drivers/rtc/rtc-at91rm9200.c | 2 +- drivers/rtc/rtc-at91sam9.c | 3 +- drivers/tty/serial/atmel_serial.c | 3 +- drivers/watchdog/at91sam9_wdt.c | 3 +- include/linux/interrupt.h | 11 ++++++ include/linux/irqdesc.h | 3 ++ kernel/irq/pm.c | 71 +++++++++++++++++++++++++++++++++++++-- 9 files changed, 109 insertions(+), 8 deletions(-) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
