From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932308AbcDKOCn (ORCPT ); Mon, 11 Apr 2016 10:02:43 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:43439 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754638AbcDKOCk (ORCPT ); Mon, 11 Apr 2016 10:02:40 -0400 Subject: Re: [PATCH v2] extcon: usb-gpio: Don't miss event during suspend/resume To: References: <1459951299-20578-1-git-send-email-rogerq@ti.com> <57075F23.8080703@ti.com> <570AF062.5000609@samsung.com> <570B6248.6080905@ti.com> <570B8686.3050306@samsung.com> <570B8CE7.3060605@ti.com> CC: Grygorii Strashko , "myungjoo.ham@samsung.com" , linux-kernel From: Roger Quadros Message-ID: <570BAE79.1020503@ti.com> Date: Mon, 11 Apr 2016 17:02:33 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/04/16 16:17, Chanwoo Choi wrote: > Hi Roger, > > On Mon, Apr 11, 2016 at 8:39 PM, Roger Quadros wrote: >> Chanwoo, >> >> On 11/04/16 14:12, Chanwoo Choi wrote: >>> On 2016년 04월 11일 17:37, Grygorii Strashko wrote: >>>> On 04/11/2016 03:31 AM, Chanwoo Choi wrote: >>>>> Hi Roger, >>>>> >>>>> On 2016년 04월 08일 16:34, Roger Quadros wrote: >>>>>> Pin state might have changed during suspend/resume while >>>>>> our interrupts were disabled and if device doesn't support wakeup. >>>>>> >>>>>> Scan for change during resume for such case. >>>>>> >>>>>> Signed-off-by: Roger Quadros >>>>>> --- >>>>>> v2: >>>>>> - only check for state change during resume if device wakeup is not supported >>>>>> >>>>>> drivers/extcon/extcon-usb-gpio.c | 2 ++ >>>>>> 1 file changed, 2 insertions(+) >>>>>> >>>>>> diff --git a/drivers/extcon/extcon-usb-gpio.c b/drivers/extcon/extcon-usb-gpio.c >>>>>> index bc61d11..118f8ab 100644 >>>>>> --- a/drivers/extcon/extcon-usb-gpio.c >>>>>> +++ b/drivers/extcon/extcon-usb-gpio.c >>>>>> @@ -185,6 +185,8 @@ static int usb_extcon_resume(struct device *dev) >>>>>> int ret = 0; >>>>>> >>>>>> enable_irq(info->id_irq); >>>>>> + if (!device_may_wakeup(dev)) >>>>>> + usb_extcon_detect_cable(&info->wq_detcable.work); >>>>> >>>>> The device_may_wakeup() check the following two states: >>>>> - dev->power.can_wakeup - device_init_wakeup() function set the this field. >>>>> - dev->power.wakeup - device_wakeup_enable() function set the this field. >>>>> >>>>> The probe function of extcon-usb-gpio.c always call the 'device_init_wakeup(dev,true). >>>>> But, anywhere in extcon-usb-gpio.c don't handle the device_wakeup_enable() for dev->power.wakeup. >>>> >>>> >>>> device_init_wakeup() >>>> |-> device_wakeup_enable() >>>> >>>>> >>>>> In the extcon-usb-gpio.c, device_may_wakeup(dev) return always 'false'. >>>>> If you use the only device_may_wakeup(), >>>>> device_may_wakeup() is not able to check whether interrupt is wakeup source or not. >>>>> >>>> >>>> This check is correct and it also will take into account wake up settings changes >>>> which can be made through sysfs: /sys/.../devX/power/wakeup >>>> >>> >>> To Grygorii, >>> >>> You're right. I was mistaken. Again, I analyzed the sequence about wakeup. >>> Thanks for your reply. >>> >>> 1. Register device as wakeup_source. >>> device_init_wakeup(dev, true) on probe() >>> device_wakeup_enable(dev) >>> device_source_register(const char *name) >>> struct wakeup_source *ws; >>> ws = wakeup_source_create(name) >>> if (ws) >>> wakeup_source_add(ws); >>> ... >>> list_add_rcu(&ws->entry, &wakeup_sources); >>> ... >>> return ws; >>> >>> >>> 2. Register the interrupt as wake_irq >>> dev_pm_set_wake_irq(struct device *dev, int irq) on probe() >>> struct wake_irq *wirq; >>> wirq->dev = dev; >>> wirq->irq = irq; >>> dev_pm_attach_wake_irq(dev, irq, wirq); >>> device_wakeup_attach_irq(*dev, *wakeirq) >>> struct wakeup_source *ws; >>> ws = dev->power.wakeup; >>> ws->wakeirq = wakeirq; >>> >>> >>> 3. Enable irq wake if device is already registed to wakeup_sources. >>> dpm_suspend_noirq() >>> device_wakeup_arm_wake_irqs() >>> list_for_each_entry_rcu(ws, &wakeup_sources, entry) { >>> if (ws->wakeirq) >>> dev_pm_arm_wake_irq(sw->wakeirq); >>> if (device_may_wakeup(wirq->dev)) >>> enable_irq_wake(wirq->irq); >>> >>> >>> To Roger, >>> >>> How about using the queue_delayed_work() instead of direct call function? >>> Because the spent time of wakeup from suspend state should be fast. >>> So, I think that you better to use the queue_delayed_work(). >>> >>> diff --git a/drivers/extcon/extcon-usb-gpio.c b/drivers/extcon/extcon-usb-gpio.c >>> index 118f8ab3be73..f6cbdfe31519 100644 >>> --- a/drivers/extcon/extcon-usb-gpio.c >>> +++ b/drivers/extcon/extcon-usb-gpio.c >>> @@ -186,7 +186,9 @@ static int usb_extcon_resume(struct device *dev) >>> >>> enable_irq(info->id_irq); >>> if (!device_may_wakeup(dev)) >>> - usb_extcon_detect_cable(&info->wq_detcable.work); >>> + queue_delayed_work(system_power_efficient_wq, >>> + &info->wq_detcable, >>> + info->debounce_jiffies); >> >> Why not to just use queue_work() instead of queue_delayed_work() >> as don't need to debounce the input? > > The use of queue_work() is good. Unfortunately we can't as info->wq_detcable type is 'struct delayed_work' but queue_work() expects 'struct work_struct' I'll just call queue_delayed_work() with 0 delay :) cheers, -roger