[PATCH 4.14 189/218] USB: hcd-pci: Fully suspend across freeze/thaw cycle

Greg Kroah-Hartman
2022-06-13T11:10:40Z

From: Evan Green <evgreen@chromium.org>

[ Upstream commit 63acaa8e9c65dc34dc249440216f8e977f5d2748 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 5340d433cdf0..18b3a5e518cd 100644
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -632,10 +632,10 @@ 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,
--
2.35.1