Commit a94f0181 authored by Artur Petrosyan's avatar Artur Petrosyan Committed by Greg Kroah-Hartman
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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: default avatarkernel test robot <lkp@intel.com>
Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Acked-by: default avatarMinas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Signed-off-by: default avatarArtur Petrosyan <Arthur.Petrosyan@synopsys.com>
Link: https://lore.kernel.org/r/20210416124827.9BB59A005D@mailhost.synopsys.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ae0da4fd

drivers/usb/dwc2/platform.c

+15 −0
Original line number Diff line number Diff line
@@ -316,8 +316,23 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg) 
static int dwc2_driver_remove(struct platform_device *dev)

{

	struct dwc2_hsotg *hsotg = platform_get_drvdata(dev);

	struct dwc2_gregs_backup *gr;

	int ret = 0;



	gr = &hsotg->gr_backup;



	/* Exit Hibernation when driver is removed. */

	if (hsotg->hibernated) {

		if (gr->gotgctl & GOTGCTL_CURMODE_HOST)

			ret = dwc2_exit_hibernation(hsotg, 0, 0, 1);

		else

			ret = dwc2_exit_hibernation(hsotg, 0, 0, 0);



		if (ret)

			dev_err(hsotg->dev,

				"exit hibernation failed.\n");

	}



	/* Exit Partial Power Down when driver is removed. */

	if (hsotg->in_ppd) {

		ret = dwc2_exit_partial_power_down(hsotg, 0, true);