linux-kernel - Re: [PATCH v2] USB:ehci:fix an interrupt calltrace error

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Tue, 12 Jan 2021 09:49:49 +0800
From:   liulongfang <liulongfang@...wei.com>
To:     Alan Stern <stern@...land.harvard.edu>
CC:     <gregkh@...uxfoundation.org>, <yisen.zhuang@...wei.com>,
        <kong.kongxinwei@...ilicon.com>, <linux-usb@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2] USB:ehci:fix an interrupt calltrace error

On 2021/1/12 1:07, Alan Stern Wrote:
> On Mon, Jan 11, 2021 at 07:29:37PM +0800, Longfang Liu wrote:
>> The system that use Synopsys USB host controllers goes to suspend
>> when using USB audio player. This causes the USB host controller
>> continuous send interrupt signal to system, When the number of
>> interrupts exceeds 100000, the system will forcibly close the
>> interrupts and output a calltrace error.
>>
>> When the system goes to suspend, the last interrupt is reported to
>> the driver. At this time, the system has set the state to suspend.
>> This causes the last interrupt to not be processed by the system and
>> not clear the interrupt flag. This uncleared interrupt flag constantly
>> triggers new interrupt event. This causing the driver to receive more
>> than 100,000 interrupts, which causes the system to forcibly close the
>> interrupt report and report the calltrace error.
>>
>> so, when the driver goes to sleep and changes the system state to
>> suspend, the interrupt flag needs to be cleared.
>>
>> Signed-off-by: Longfang Liu <liulongfang@...wei.com>
> 
> Acked-by: Alan Stern <stern@...land.harvard.edu>
> OK, I will add it on the next patch
Thanks,
Longfang
>> ---
>>
>> Changes in v2:
>> - updated cleared registers
>>
>>  drivers/usb/host/ehci-hub.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
>> index ce0eaf7..a99c1ac 100644
>> --- a/drivers/usb/host/ehci-hub.c
>> +++ b/drivers/usb/host/ehci-hub.c
>> @@ -346,8 +346,12 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
>>  
>>  	unlink_empty_async_suspended(ehci);
>>  
>> +	/* Some Synopsys controllers mistakenly leave IAA turned on */
>> +	ehci_writel(ehci, STS_IAA, &ehci->regs->status);
>> +
>>  	/* Any IAA cycle that started before the suspend is now invalid */
>>  	end_iaa_cycle(ehci);
>> +
>>  	ehci_handle_start_intr_unlinks(ehci);
>>  	ehci_handle_intr_unlinks(ehci);
>>  	end_free_itds(ehci);
>> -- 
>> 2.8.1
>>
> .
>