USB: hcd-pci: Fully suspend across freeze/thaw cycle
authorEvan Green <evgreen@chromium.org>
Thu, 21 Apr 2022 17:39:27 +0000 (10:39 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 14 Jun 2022 16:36:21 +0000 (18:36 +0200)
commitfeb0fb39695b9f627c3f15a39fea8ee090e2f8fc
treef315ede791771c5eaddb7680457e23ca7ebb6cc4
parentd888753872190abd18f68a7d77b9c7c367f0a7ab
USB: hcd-pci: Fully suspend across freeze/thaw cycle

[ 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