Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH] USB:ohci:fix ohci interruption problem
To:     <gregkh@linuxfoundation.org>, <mathias.nyman@intel.com>,
        <stern@rowland.harvard.edu>
CC:     <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <kong.kongxinwei@hisilicon.com>, <yisen.zhuang@huawei.com>
References: <1617354660-43964-1-git-send-email-liulongfang@huawei.com>
From:   liulongfang <liulongfang@huawei.com>
Message-ID: <c1ce8b17-350f-8de4-5f9e-2282073916ad@huawei.com>
Date:   Fri, 2 Apr 2021 17:26:49 +0800
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101
 Thunderbird/60.8.0
MIME-Version: 1.0
In-Reply-To: <1617354660-43964-1-git-send-email-liulongfang@huawei.com>
Content-Type: text/plain; charset="gbk"
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 2021/4/2 17:11, Longfang Liu wrote:
> The operating method of the system entering S4 sleep mode:
> echo disk > /sys/power/state
> 
> When OHCI enters the S4 sleep state, the USB sleep process will call
> check_root_hub_suspend() and ohci_bus_suspend() instead of
> ohci_suspend() and ohci_bus_suspend(), this causes the OHCI interrupt
> to not be closed.
> 
> At this time, if just one device interrupt is reported. Since rh_state
> has been changed to OHCI_RH_SUSPENDED after ohci_bus_suspend(), the
> driver will not process and close this device interrupt. It will cause
> the entire system to be stuck during sleep, causing the device to
> fail to respond.
> 
> When the abnormal interruption reaches 100,000 times, the system will
> forcibly close the interruption and make the device unusable.
> 
> Because the root cause of the problem is that ohci_suspend is not
> called to perform normal interrupt shutdown operations when the system
> enters S4 sleep mode.
> 
> Therefore, our solution is to specify freeze interface in this mode to
> perform normal suspend_common() operations, and call ohci_suspend()
> after check_root_hub_suspend() is executed through the suspend_common()
> operation.
> After using this solution, it is verified by the stress test of sleep
> wake up in S4 mode for a long time that this problem no longer occurs.
> 
> Signed-off-by: Longfang Liu <liulongfang@huawei.com>
> ---
>  drivers/usb/core/hcd-pci.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
> index 1547aa6..78a56cd 100644
> --- a/drivers/usb/core/hcd-pci.c
> +++ b/drivers/usb/core/hcd-pci.c
> @@ -509,6 +509,11 @@ static int resume_common(struct device *dev, int event)
>  
>  #ifdef	CONFIG_PM_SLEEP
>  
> +static int hcd_pci_freeze(struct device *dev)
> +{
> +	return suspend_common(dev, device_may_wakeup(dev));
> +}
> +
>  static int hcd_pci_suspend(struct device *dev)
>  {
>  	return suspend_common(dev, device_may_wakeup(dev));
> @@ -605,8 +610,8 @@ const struct dev_pm_ops usb_hcd_pci_pm_ops = {
>  	.suspend_noirq	= hcd_pci_suspend_noirq,
>  	.resume_noirq	= hcd_pci_resume_noirq,
>  	.resume		= hcd_pci_resume,
> -	.freeze		= check_root_hub_suspended,
> -	.freeze_noirq	= check_root_hub_suspended,
> +	.freeze		= hcd_pci_freeze,
> +	.freeze_noirq	= hcd_pci_freeze,
>  	.thaw_noirq	= NULL,
>  	.thaw		= NULL,
>  	.poweroff	= hcd_pci_suspend,
> 
Sorry, please ignore this patch, I will resend it.
Thanks.
Longfang.