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Message-ID: <YGcZQiBx3mCzqkPd@kroah.com>
Date: Fri, 2 Apr 2021 15:16:50 +0200
From: Greg KH <gregkh@...uxfoundation.org>
To: Longfang Liu <liulongfang@...wei.com>
Cc: mathias.nyman@...el.com, stern@...land.harvard.edu,
linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
kong.kongxinwei@...ilicon.com, yisen.zhuang@...wei.com
Subject: Re: [PATCH] USB:ohci:fix ohci interruption problem
On Fri, Apr 02, 2021 at 05:27:59PM +0800, 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@...wei.com>
> ---
> drivers/usb/core/hcd-pci.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
What changed from the previous version sent for this patch? Always
properly describe the changes below the --- line, and also version your
subject line as documented.
Please fix up and resend.
thanks,
greg k-h
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