2013/12/23 MyungJoo Ham <myungjoo....@samsung.com>: >> On 12/23/2013 05:13 PM, Barry Song wrote: >> > 2013/12/23 Chanwoo Choi <cw00.c...@samsung.com>: >> >> On 12/23/2013 04:36 PM, Barry Song wrote: >> >>> 2013/12/23 Chanwoo Choi <cw00.c...@samsung.com>: >> >>>> On 12/23/2013 03:10 PM, Barry Song wrote: >> >>>>> 2013/12/23 Chanwoo Choi <cw00.c...@samsung.com>: >> >>>>>> On 12/20/2013 05:09 PM, rjying wrote: >> >>>>>>> From: Rongjun Ying <rongjun.y...@csr.com> >> >>>>>>> >> >>>>>>> After system resume, need send extcon uevent to userspace >> >>>>>> >> >>>>>> Why did extcon send uevent after wakeup from suspend? >> >>>>>> >> >>>>>> If extcon cable is attatched or detached on suspend state, >> >>>>>> Kernel can detect the interrupt about changed state of extcon. >> >>>>> >> >>>>> irq controller has lost power in suspend, so there is no pending >> >>>>> interrupt. >> >>>>> and HW will not pend any interrupt when we hotplug cable during sleep. >> >>>> >> >>>> No, SoC in suspend state must maintain the minimum power under 1mA >> >>>> if completed the power-optimization on suspend state. >> >>>> >> >>>> If user insert USB cable to target, the external interrupt connected to >> >>>> USB port is happened. And kernel would be waked up from suspend state >> >>>> to operate proper interrupt handler of external interrupt. >> >>> >> >>> no. not every USB supports that. that depends on the power domain design >> >>> of SoC. >> >> >> >> USB is only example for gpio control in suspend state. >> >> >> >>> >> >>>> >> >>>> Also, >> >>>> Input subsystem used gpio-keys driver for power button.. >> >>>> If user press power button in suspend state, target would be waked up >> >>>> from suspend state. >> >>>> It is same case both extcon gpio and gpio-keys of input subsystem. >> >>> >> >>> no. it depends on the SoC design. many SoC only support 1 special key >> >>> which can work as ON-KEY as wakeup source. and this kind of keys might >> >>> not be GPIO at all. >> >>> there is a special power domain which is still open for it. >> >> >> >> many SoC? >> >> >> >> As I knew, most SoC has supported various wakeup source. >> >> As you comment, if specific SoC support only one special key >> >> for wakeup from suspend state, I think it isn't common. >> >> >> >> Also, >> >> This patch isn't necessary on SoCs which support various wakeup source >> >> (e.g., external interrupt). >> >> As you comment, this issue has dependecy on specific SoC. Why did you >> >> think this common code? >> > >> > i am not thinking this patch must be common codes but i think the >> > extcon should provide common codes to support all chips. that is what >> > a framework should consider. >> > >> > if there is no this or things similar with this, how could extcon >> > support the chips which don't support receiving sleep gpio interrupts? >> >> Sure, subsystem should support all cases related to this issue. >> >> I'd like to send common patch to support all cases as we discussed. >> If some patch support all case, I would review and apply it. >> >> Chanwoo Choi > > Dear Barry and Chanwoo, > > > What about having a flag in extcon platform data that describes > whether this extcon-gpio requires status double checking at resume > or not?
MyungJoo, Thanks! i am ok. what about naming it as "bool lost_sleep_irq"? default, it is 0, for chips that will lose sleeping IRQ, set it to 1? Chanwoo, how do you think? > > > Cheers, > MyungJoo > -barry -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
