On Friday 22 May 2009, Kim Kyuwon wrote:> 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() and> arch_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? I think it would happen anyway with the old code, wouldn't it? Best,Rafael_______________________________________________linux-pm mailing listlinux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx://lists.linux-foundation.org/mailman/listinfo/linux-pm
