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Message-ID: <ed353f12-7ba7-1831-2ac7-b6135b2a5abb@gmail.com>
Date:   Mon, 26 Jun 2023 10:28:26 +0800
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Subject: Re: [PATCH v2] usb: ohci-at91: Fix the unhandle interrupt when resume
To:     Alan Stern <stern@rowland.harvard.edu>
Cc:     gregkh@linuxfoundation.org, nicolas.ferre@microchip.com,
        alexandre.belloni@bootlin.com, claudiu.beznea@microchip.com,
        linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
References: <20230625161553.11073-1-aarongt.shen@gmail.com>
 <552b1ac6-2149-48fa-9432-49655bfbc366@rowland.harvard.edu>
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From:   Guiting Shen <aarongt.shen@gmail.com>
In-Reply-To: <552b1ac6-2149-48fa-9432-49655bfbc366@rowland.harvard.edu>
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On Mon, Jun 26, 2023 at 04:04:29AM GMT+8, Alan Stern wrote:
> On Mon, Jun 26, 2023 at 12:15:53AM +0800, Guiting Shen wrote:
>> The ohci_hcd_at91_drv_suspend() sets ohci->rh_state to OHCI_RH_HALTED when
>> suspend which will let the ohci_irq() skip the interrupt after resume. And
>> nobody to handle this interrupt.
>>
>> According to the comment in ohci_hcd_at91_drv_suspend(), it need to reset
>> when resume from suspend(MEM) to fix.
>>
>> Signed-off-by: Guiting Shen <aarongt.shen@gmail.com>
>> ---
>>  drivers/usb/host/ohci-at91.c | 7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c
>> index b9ce8d80f20b..1a0356d9ea15 100644
>> --- a/drivers/usb/host/ohci-at91.c
>> +++ b/drivers/usb/host/ohci-at91.c
>> @@ -672,7 +672,12 @@ ohci_hcd_at91_drv_resume(struct device *dev)
>>  	else
>>  		at91_start_clock(ohci_at91);
>>  
>> -	ohci_resume(hcd, false);
>> +	/*
>> +	 * need to reset according to the comment of suspend routine,
>> +	 * otherwise the ohci_irq would skip the interrupt if ohci_state
>> +	 * was OHCI_RH_HALTED.
>> +	 */
>> +	ohci_resume(hcd, !ohci_at91->wakeup);
> 
> This comment doesn't say why the code uses !ohci_at91->wakeup.  It 
> should explain that.  For example:
> 
> 	/*
> 	 * According to the comment in ohci_hcd_at91_drv_suspend()
> 	 * we need to do a reset if the 48-MHz clock was stopped,
> 	 * that is, if ohci_at91->wakeup is clear.  Tell ohci_resume()
> 	 * to reset in this case by setting its "hibernated" flag.
> 	 */
> 

Ok, Thank you!
Do I send the v3 patch after the merge window close?

-- 
Regards,
Guiting Shen