| Message ID | 20220418135819.v2.2.I8226c7fdae88329ef70957b96a39b346c69a914e@changeid |
|---|---|
| State | Superseded |
| Headers | show |
| Series | USB: Quiesce interrupts across pm freeze | expand |
On Mon, Apr 18, 2022 at 02:00:46PM -0700, Evan Green wrote: > The documentation for the freeze() method says that it "should quiesce > the device so that it doesn't generate IRQs or DMA". The unspoken > consequence of not doing this is that MSIs aimed at non-boot CPUs may > get fully lost if they're sent during the period where the target CPU is > offline. > > The current callbacks for USB HCD do not fully quiesce interrupts, > specifically on XHCI. Change to use the full suspend/resume flow for > freeze/thaw to ensure interrupts are fully quiesced. This fixes issues > where USB devices fail to thaw during hibernation because XHCI misses > its interrupt and cannot recover. > > Signed-off-by: Evan Green <evgreen@chromium.org> > > --- Acked-by: Alan Stern <stern@rowland.harvard.edu> > Changes in v2: > - Added the patch modifying the remote wakeup state That wasn't a change to this patch. No matter. > - Removed the change to freeze_noirq/thaw_noirq > > drivers/usb/core/hcd-pci.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c > index 8176bc81a635d6..ae5e6d572376be 100644 > --- a/drivers/usb/core/hcd-pci.c > +++ b/drivers/usb/core/hcd-pci.c > @@ -616,10 +616,10 @@ 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_suspend, > .freeze_noirq = check_root_hub_suspended, > .thaw_noirq = NULL, > - .thaw = NULL, > + .thaw = hcd_pci_resume, > .poweroff = hcd_pci_suspend, > .poweroff_noirq = hcd_pci_suspend_noirq, > .restore_noirq = hcd_pci_resume_noirq,
diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c index 8176bc81a635d6..ae5e6d572376be 100644 --- a/drivers/usb/core/hcd-pci.c +++ b/drivers/usb/core/hcd-pci.c @@ -616,10 +616,10 @@ 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_suspend, .freeze_noirq = check_root_hub_suspended, .thaw_noirq = NULL, - .thaw = NULL, + .thaw = hcd_pci_resume, .poweroff = hcd_pci_suspend, .poweroff_noirq = hcd_pci_suspend_noirq, .restore_noirq = hcd_pci_resume_noirq,
The documentation for the freeze() method says that it "should quiesce the device so that it doesn't generate IRQs or DMA". The unspoken consequence of not doing this is that MSIs aimed at non-boot CPUs may get fully lost if they're sent during the period where the target CPU is offline. The current callbacks for USB HCD do not fully quiesce interrupts, specifically on XHCI. Change to use the full suspend/resume flow for freeze/thaw to ensure interrupts are fully quiesced. This fixes issues where USB devices fail to thaw during hibernation because XHCI misses its interrupt and cannot recover. Signed-off-by: Evan Green <evgreen@chromium.org> --- Changes in v2: - Added the patch modifying the remote wakeup state - Removed the change to freeze_noirq/thaw_noirq drivers/usb/core/hcd-pci.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)