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usb: dwc2: Add exit hibernation mode before removing drive
authorArtur Petrosyan <Arthur.Petrosyan@synopsys.com>
Fri, 16 Apr 2021 12:48:26 +0000 (16:48 +0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 22 Apr 2021 09:55:34 +0000 (11:55 +0200)
commita94f01814be4fb46fb89c08209f808b665182763
treee0cc5dd70203d5114584524908fd8666347a782c
parentae0da4fd225804a2c5c60a03b16fcf7d930d8581
usb: dwc2: Add exit hibernation mode before removing drive

When dwc2 core is in hibernation mode loading
driver again causes driver fail. Because in
that mode registers are not accessible.

In order to exit from hibernation checking
dwc2 core power saving state in "dwc2_driver_remove()"
function. If core is in hibernation, then checking the
operational mode of the driver. To check whether dwc2 core
is operating in host mode or device mode there is one way
which is retrieving the backup value of "gotgctl" and compare
the "CurMod" value. If previously core entered hibernation
in host mode then the exit is performed for host if not then
exit is performed for device mode. The introduced checking
is because in hibernation state all registers are not
accessible.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com>
Link: https://lore.kernel.org/r/20210416124827.9BB59A005D@mailhost.synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/dwc2/platform.c