usb: ohci-platform: fix usb disconnect issue after s4
The ohci retaining bogus hardware states cause usb disconnect devices
connected before hibernation(s4), this issue occur when ohci-platform
driver build as a module and the built-in ohci-platform driver will
re probe and re enumerate the devices, so there will be no such problem.
Avoid retaining bogus hardware states during resume-from-hibernation.
Previously we had reset the hardware as part of preparing to reinstate
the snapshot image. But we can do better now with the new PM framework,
since we know exactly which resume operations are from hibernation.
According to the commit '
cd1965db054e ("USB: ohci: move ohci_pci_{
suspend,resume} to ohci-hcd.c")' and commit '
6ec4beb5c701 ("USB: new
flag for resume-from-hibernation")', the flag "hibernated" is for
resume-from-hibernation and it should be true when usb resume from disk.
When this flag "hibernated" is set, the drivers will reset the hardware
to get rid of any existing state and make sure resume from hibernation
re-enumerates everything for ohci.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Yinbo Zhu <zhuyinbo@loongson.cn>
Link: https://lore.kernel.org/r/20220902063639.17875-1-zhuyinbo@loongson.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>