Re: [PATCH v2] USB:ohci:fix ohci interruption problem

From: Alan Stern
Date: Fri Apr 09 2021 - 11:07:49 EST


On Fri, Apr 09, 2021 at 03:47:02PM +0800, Longfang Liu wrote:
> The operating method of the system entering S4 sleep mode:
> echo reboot > /sys/power/disk
> echo disk > /sys/power/state
>
> When OHCI enters the S4 sleep state, check the log and find that
> the USB sleep process will call check_root_hub_suspend() and
> ohci_bus_suspend() instead ohci_suspend() and ohci_bus_suspend(),
> which will cause the OHCI interrupt to not be closed.
>
> At this time, if just one device interrupt is reported. 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.
>
> Signed-off-by: Longfang Liu <liulongfang@xxxxxxxxxx>
> ---
>
> Changes in V2:
> - Modify comment and patch version information.

Please, instead of sending the same incorrect patch over and over again,
spend some time figuring out what is really going wrong. I have already
explained why this patch is not the right thing to do.

You have to determine why the poweroff callback in hcd-pci.c (which
points to hcd_pci_suspend) isn't getting called. That's the real
explanation for your problem.

Alan Stern

> Changes in V1:
> - Call suspend_common by adding the hcd_pci_freeze function turn off
> the interrupt instead of adding a shutdown operation in ohci_bus_suspend
> to turn off the interrupt.
>
> drivers/usb/core/hcd-pci.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
> index 1547aa6..c5844a3 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));
> @@ -605,7 +610,7 @@ 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 = hcd_pci_freeze,
> .freeze_noirq = check_root_hub_suspended,
> .thaw_noirq = NULL,
> .thaw = NULL,
> --
> 2.8.1
>