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Message-ID: <0b24b79b-b412-7e2b-c0a6-5b6f9ed5a90d@ti.com>
Date:   Mon, 7 Mar 2022 18:51:11 +0530
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Subject: Re: [PATCH V1] extcon/usb: Remove disable irq operation in system
 sleep.
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To:     Roger Quadros <rogerq@kernel.org>,
        Bruce Chen <brucechen251@gmail.com>, <bruce.chen@unisoc.com>,
        <myungjoo.ham@samsung.com>, <cw00.choi@samsung.com>,
        <linux-kernel@vger.kernel.org>,
        Aswath Govindraju <a-govindraju@ti.com>
CC:     <orsonzhai@gmail.com>, <gengcixi@gmail.com>,
        <baolin.wang7@gmail.com>, <zhang.lyra@gmail.com>
References: <1646292963-20570-1-git-send-email-brucechen251@gmail.com>
 <32165383-5ccf-e6a1-92ef-cde14c401eaa@kernel.org>
From:   Vignesh Raghavendra <vigneshr@ti.com>
In-Reply-To: <32165383-5ccf-e6a1-92ef-cde14c401eaa@kernel.org>
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Precedence: bulk

Hi,

On 03/03/22 2:50 pm, Roger Quadros wrote:
> +TI folks Aswath & Vignesh.
> 

Thanks for looping in.

> Hi Bruce,
> 
> On 03/03/2022 09:36, Bruce Chen wrote:
>> From: Bruce Chen <bruce.chen@unisoc.com>
>>
>> If disable vbus/id irq, it will lead to wakeup system fail
>> in unisoc platform. In unisoc platform, Irq enable and irq
>> wakeup are the same interrupt line. So remove disable vbus/id
>> irq operation is a way to solve the issue> 
>> Signed-off-by: Bruce Chen <bruce.chen@unisoc.com>
>> ---
>>  drivers/extcon/extcon-usb-gpio.c | 15 ---------------
>>  1 file changed, 15 deletions(-)
>>
>> diff --git a/drivers/extcon/extcon-usb-gpio.c b/drivers/extcon/extcon-usb-gpio.c
>> index f2b65d9..40d967a 100644
>> --- a/drivers/extcon/extcon-usb-gpio.c
>> +++ b/drivers/extcon/extcon-usb-gpio.c
>> @@ -226,16 +226,6 @@ static int usb_extcon_suspend(struct device *dev)
>>  		}
>>  	}
>>  
>> -	/*
>> -	 * We don't want to process any IRQs after this point
>> -	 * as GPIOs used behind I2C subsystem might not be
>> -	 * accessible until resume completes. So disable IRQ.
>> -	 */
> 
> I think the reason this was added was that if USB cable is plugged/unplugged
> while system was suspending it was causing some faults on TI DRA7 EVM
> at usb_irq_handler()/usb_extcon_detect_cable() when it tries to read GPIO status
> when I2C based GPIO controller was used but already suspended.
> But looks like disabling the IRQ is not the right approach either so your patch
> is right.
> 
> However I'm not sure if the above issue will still exist on DRA7 and other TI EVMS
> using ID/VBUS GPIO over I2C device.
> 
> Let's wait for Aswath/Vignesh to confirm. If no issues I'm OK with this patch.


Support for suspend/resume on DRA7x isn't really maintained actively.
Hence, cannot really test the patch. But, no objections for this patch
either.

[...]

Regards
Vignesh