On Fri, May 22, 2009 at 11:53 AM, Kim Kyuwon <chammoru@xxxxxxxxx> wrote:> On Wed, May 6, 2009 at 8:27 AM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:>> On Wednesday 06 May 2009, Kevin Hilman wrote:>>> Arve Hjønnevåg <arve@xxxxxxxxxxx> writes:>>>>>> > On Tue, May 5, 2009 at 8:52 AM, Kevin Hilman>>> > <khilman@xxxxxxxxxxxxxxxxxxx> wrote:>>> >> Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> writes:>>> >>>>> >>> On Mon, 4 May 2009 17:27:04 -0700 Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx> wrote:>>> >>>>>> >>>> Interrupts that are flagged as wakeup sources via set_irq_wake()>>> >>>> should not be disabled for suspend.>>> >>>>>>> >>>>>> >>> Why not?>>> >>>>>> >>>>> >> If an interrupt is a wakeup source, and it is disabled at the chip>>> >> level, it will no longer generate interrupts, and thus no longer wake>>> >> up the system.>>> >>>>> >> I'd be interested in hearing why wakeup interrupts should be disabled>>> >> during suspend.>>>> That depends on whether or not they are used for anything else than wake-up.>>>>>>>> [...]>>>>>> >>>>>> >>> If this fixes some bug then please provide a description of that bug?>>> >>>>> >> The bug is that on TI OMAP, interrupts that are used for wakeup events>>> >> are disabled by this code causing the system to no longer wake up.>>> >>>> > What do you do if the interrupt triggers right after your driver has>>> > returned from its late suspend hook?>>>>>> If it's a wakeup IRQ, I assume you want it to prevent suspend.>>>>>> But I don't see how that can happen in the current code. IIUC, by the>>> time your late suspend hook is run, your device IRQ is already>>> disabled, so it won't trigger an interrupt that will be caught by>>> check_wakeup_irqs() anyways.>>>> My understanding of __disable_irq() was that it didn't actually disable the>> IRQ at the hardware level, allowing the CPU to actually receive the interrupt>> and acknowledge it, but preventing the device driver for receiving it. Does>> it work differently on the affected systems?>> Hi, Rafael.> Sorry for bring the old issue but please let me ask you about> suspend_device_irqs() function.>> __disable_irq() disables the IRQ at the hardware level in the> following irq_chips>> i8259A_chip> i8259_pic> i8259A_chip> bfin_internal_irqchip> crisv10_irq_type> crisv32_irq_type> h8300irq_chip> m_irq_chip> mn10300_cpu_pic_level> xtensa_irq_chip> iop13xx_msi_chip> msi_irq>> Because these irq_chips mask interrupts in 'disable' hook.>> Thus, your suspend_device_irqs() function disables all IRQs at the> hardware level on all architectures which use irq_chips listed above> in suspend state.> Is this really what you wanted?>> If interrupt can wake up the system from suspend in some architectures> and if disable_irq_wake is not supported in these architectures, I> wonder if suspend_device_irqs() don't allow waking up by interrupt.>> Regards,> Kyuwon> I saw resume_device_irqs() is invoked after arch_suspend_enable_irqs()in your resume code.So in this gap between resume_device_irqs() andarch_suspend_enable_irqs(), a few interrupts would be discarded.i.e, a few data would be lost. If keypad wake up the system, first key pressed information would be lost.If I2C, USB, SPI, UART wake up the system, first a few data would be lost. Did you also consider this issue? -- Kyuwon (규원)_______________________________________________linux-pm mailing listlinux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx://lists.linux-foundation.org/mailman/listinfo/linux-pm
