On Sat, May 30, 2009 at 4:34 PM, Kim Kyuwon <chammoru@xxxxxxxxx> wrote:> On Sat, May 30, 2009 at 8:35 AM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:>> On Monday 25 May 2009, Kim Kyuwon wrote:>>> Rafael J. Wysocki wrote:>>> > On Saturday 23 May 2009, Kim Kyuwon wrote:>>> >> On Sat, May 23, 2009 at 7:29 AM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:>>> >>> On Saturday 23 May 2009, Kim Kyuwon wrote:>>> > [--snip--]>>> >>>> You changed the really important part of Linux, which may affect most>>> >>>> processor architectures. I think you should be careful. If some of>>> >>>> architectures can't take care of it (they can implement>>> >>>> disable_irq_wake correctly in H/W level, will you revert your changes?>>> >>> No, the changes are not going to be reverted. In fact things should have been>>> >>> done like this already much earlier.>>> >>>>>> >>> Now, do you have any particular example of a problem related to these changes>>> >>> or is it only a theoretical issue?>>> >> I'd CCing you when I'm sending a mail for this particular example of a example.>>> >> http://markmail.org/thread/fvt7d62arofon5xx>>> >>>> > Well, as I said above, reverting the changes that introduced>>> > [suspend|resume]_device_irqs() is not an option, becuase it was the only sane>>> > way to achieve the goal they were added for. So, we need to fix the wake-up>>> > problem on your platform with the assumption that>>> > [suspend|resume]_device_irqs() are going to stay.>>> >>>> > For starters, would it be possible to teach the 'disable' hook of your>>> > platform's interrupt controller not to mask the IRQs that have both>>> > IRQ_WAKEUP and IRQ_SUSPENDED set? That apparently would work around the>>> > wake-up interrupts problem.>>>>>> Thank you for considering this issue and spending your time. In order to>>> make your idea work, we need to add a dummy 'set_wake' hook which>>> returns always zero. Anyway, IMO, I think your idea is good to work>>> around this problem. But Kevin Hilman(OMAP PM Maintainer) would make>>> final decision.>>>>>> Buy the way, how can you handle the problem that a few interrupt are>>> discarded in a small window? I can be sure they are discarded, because I>>> have debugged defects which generate in sleep/resume state hundreds of>>> times on ARM Processors(PXA310, S3C6410, OMAP3430). Wake-up interrupts>>> are generated as soon as arch_suspend_enable_irqs() invoked.>>>> Sorry for the delayed response.>>>> If the wake-up interrupts are not masked, they will be delivered to the drivers>> as soon as arch_suspend_enable_irqs() has run. So, if the drivers are able to>> handle them at this point (ie. before resume_device_irqs() is called), they>> won't be lost.>> Thank you for your response!>> Your suspend_device_irqs() disables all IRQs(except timer IRQ) while> entering suspend. i.e. Before invoking resume_device_irqs() or> resume_noirq callback, all IRQs(except timer IRQ) is in IRQ_DISABLED> status. Right?> But if an IRQ is in IRQ_DISABLED status, its interrupt handler can be Sorry: *Can't be* > invoked. (As you know, all IRQs with IRQ_DISABLE are not handled in> handle_level_irq function). Thus, even if the wake-up interrupts are> not masked, the drivers are not able to handle interrupts, because the> interrupt handler can't be invoked due to IRQ_DISABLED set by> suspend_device_irqs().>>> The only problem I see is that the drivers may expect their>> ->resume_noirq() callbacks to be executed first.>> resume_noirq() callbacks are also invoked after arch_suspend_enable_irqs().>> Regards,> Kyuwon> -- Kyuwon (규원)_______________________________________________linux-pm mailing listlinux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx://lists.linux-foundation.org/mailman/listinfo/linux-pm
