Re: [PATCH v4] USB: Fix the issue of task recovery failure caused by USB status when S4 wakes up

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Oct 24, 2024 at 04:46:48PM +0800, duanchenghao wrote:
> hi greg k-h,
> 
> 在 2024-10-24星期四的 09:05 +0200，Greg KH写道：
> > On Thu, Oct 24, 2024 at 10:40:38AM +0800, Duan Chenghao wrote:
> > > When a device is inserted into the USB port and an S4 wakeup is
> > > initiated,
> > > after the USB-hub initialization is completed, it will
> > > automatically enter
> > > suspend mode. Upon detecting a device on the USB port, it will
> > > proceed with
> > > resume and set the hcd to the HCD_FLAG_WAKEUP_PENDING state. During
> > > the S4
> > > wakeup process, peripherals are put into suspend mode, followed by
> > > task
> > > recovery. However, upon detecting that the hcd is in the
> > > HCD_FLAG_WAKEUP_PENDING state, it will return an EBUSY status,
> > > causing the
> > > S4 suspend to fail and subsequent task recovery to not proceed.
> > > -
> > > [   27.594598][ 1]  PM: pci_pm_freeze(): hcd_pci_suspend+0x0/0x28
> > > returns -16
> > > [   27.594601][ 1]  PM: dpm_run_callback(): pci_pm_freeze+0x0/0x100
> > > returns -16
> > > [   27.603420][ 1]  ehci-pci 0000:00:04.1: pci_pm_freeze+0x0/0x100
> > > returned 0 after 3 usecs
> > > [   27.612233][ 1]  ehci-pci 0000:00:05.1: pci_pm_freeze+0x0/0x100
> > > returned -16 after 17223 usecs
> > > [   27.810067][ 1]  PM: Device 0000:00:05.1 failed to quiesce
> > > async: error -16
> > > [   27.816988][ 1]  PM: quiesce of devices aborted after 1833.282
> > > msecs
> > > [   27.823302][ 1]  PM: start quiesce of devices aborted after
> > > 1839.975 msecs
> > > ......
> > > [   31.303172][ 1]  PM: recover of devices complete after 3473.039
> > > msecs
> > > [   31.309818][ 1]  PM: Failed to load hibernation image,
> > > recovering.
> > > [   31.348188][ 1]  PM: Basic memory bitmaps freed
> > > [   31.352686][ 1]  OOM killer enabled.
> > > [   31.356232][ 1]  Restarting tasks ... done.
> > > [   31.360609][ 1]  PM: resume from hibernation failed (0)
> > > [   31.365800][ 1]  PM: Hibernation image not present or could not
> > > be loaded.
> > > 
> > > The "do_wakeup" is determined based on whether the controller's
> > > power/wakeup attribute is set. The current issue necessitates
> > > considering
> > > the type of suspend that is occurring. If the suspend type is
> > > either
> > > PM_EVENT_FREEZE or PM_EVENT_QUIESCE, then "do_wakeup" should be set
> > > to
> > > false.
> > > 
> > > Reported-by: kernel test robot <lkp@intel.com>
> > > Closes:
> > > https://lore.kernel.org/oe-kbuild-all/202410151722.rfjtknRz-lkp@intel.com/
> > > Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
> > > Signed-off-by: Duan Chenghao <duanchenghao@kylinos.cn>
> > 
> > What commit id does this fix?
> 
> The current patch is not intended to fix an issue with a specific
> commit, but rather to address a long-standing problem in the USB core.

So should it be backported to older stable kernels?  If so, how far
back?

> > And I missed where Alan provided a signed-off-by, where was that?
> 
> In the following email, Alan proposed using "Signed-off-by" for
> signing.
> https://lore.kernel.org/all/489805e7-c19c-4b57-9cd7-713e075261cd@rowland.harvard.edu/

Ah, missed that, sorry.

thanks,

greg k-h