On 2014/4/18 7:54, Dmitry Torokhov wrote: > Hi Aubrey, > > On Fri, Apr 18, 2014 at 12:42:24AM +0800, Li, Aubrey wrote: >> On 2014/4/16 20:35, Laxman Dewangan wrote: >>> On Tuesday 15 April 2014 09:48 PM, Li, Aubrey wrote: >>>> On 2014/4/15 20:38, Laxman Dewangan wrote: >>>>> On Monday 14 April 2014 09:12 PM, Li, Aubrey wrote: >>>>>> ping... >>>>>> >>>>>> On 2014/4/10 18:48, One Thousand Gnomes wrote: >>>>>>> >>>>> I think when we say irq_wake_enable() then based on underlying HW, it >>>>> should not turn off the irq if it is require for the wakeup. I mean it >>>>> need to be handle in the hw specific callbacks to keep enabling the >>>>> wakeup irq on suspend also. >>>> I failed to see why this can't be generic to all of the GPIO buttons for >>>> suspend wakeup. Do you see any cases broken by this proposal? >>> >>> My point here is that if underlying HW needs to have irq enabled for >>> wakup then it need to handle in centralized location i.e. the driver >>> which is implementing it for the irq callbacks. >>> Otherwise, we need to change this on multiple places who needs wakeups >>> which is vast in nature like sd driver for sdcard insert/remove etc. >>> almost all drivers which need wakeups through GPIOs. >> >> I think we have to handle this driver by driver. I didn't see how can we >> make it in a centralized location. Looking forward to see your proposal. >> >>> >>>>> For me, I have key which is interrupt based from PMIC, not based on GPIO >>>>> and on that if I set it to IRQF_EARLY_RESUME then it works fine. >>>>> >>>> IRQF_NO_SUSPEND - Do not disable this IRQ during suspend >>>> IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device >>>> resume time. >>>> >>>> IRQF_NO_SUSPEND is exactly what I want, instead of IRQF_EARLY_RESUME. >>>> Can you please send your proposal/code to help me understand why this >>>> has to hw specific and why IRQF_EARLY_RESUME is better than >>>> IRQF_NO_SUSPEND? >>> >>> IRQF_EARLY_RESUME helps to re-enable mask or irq before parent interrupt >>> resume and so parent isr handler sees the irq flag enabled when it try >>> to scan source of interrupt. Otherwise parent isr handler treat this as >>> spurious interrupt and does not call handler as irq flag disabled for that. >>> >>> This only happen when on resume, parent inettrupt enabled before the >>> child interrupt on irq resume. Because as soon as parent isr re-enabled >>> on resume, its hadnler get called before actually child interrupt >>> enabled. This is what I observed mainly on PMIC and its sub irq. Not >>> observed on SoC level of interrupts. >>> >> >> This is expected behavior. I think I still need IRQF_NO_SUSPEND here. >> What I want is, this IRQ is able to generate pm wakeup event to wake the >> system up. It's enough for my case. > > The driver does call enable_irq_wake() in its suspend routine to prepare > the interrupt in question to be used as a wakeup source. Why isn't it > enough? It seems to me that your platform code should properly handle > this case instead of relying on the driver to modify IRQ flags. Yes, gpio_keys_suspend() does call enable_irq_wake() to enable the irq of the button. So when the button is pressed, hardware interrupt from this irq does occur. However, after gpio_keys_suspend(), irq_desc of this irq will be disabled if there is no IRQF_NO_SUSPEND flag. So when the hardware interrupt occurs, the irq handler won't call the action of the irq desc. That is, for this case, even if the driver call enable_irq_wake() during suspend, the irq handler in this driver won't be called because it's an action handler, not a irq handler. Does this make sense? Thanks, -Aubrey -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
