Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

USB: hcd-pci: Fully suspend across freeze/thaw cycle

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.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Evan Green <evgreen@chromium.org>
Link: https://lore.kernel.org/r/20220421103751.v3.2.I8226c7fdae88329ef70957b96a39b346c69a914e@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

authored by

Evan Green and committed by
Greg Kroah-Hartman
63acaa8e 9671d550

+2 -2
+2 -2
drivers/usb/core/hcd-pci.c
··· 615 615 .suspend_noirq = hcd_pci_suspend_noirq, 616 616 .resume_noirq = hcd_pci_resume_noirq, 617 617 .resume = hcd_pci_resume, 618 - .freeze = check_root_hub_suspended, 618 + .freeze = hcd_pci_suspend, 619 619 .freeze_noirq = check_root_hub_suspended, 620 620 .thaw_noirq = NULL, 621 - .thaw = NULL, 621 + .thaw = hcd_pci_resume, 622 622 .poweroff = hcd_pci_suspend, 623 623 .poweroff_noirq = hcd_pci_suspend_noirq, 624 624 .restore_noirq = hcd_pci_resume_noirq,