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@xxxxxxxxxx>
> ---
> 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.
