[PATCH] usb: dwc3: xilinx: add shutdown callback

Adds a shutdown callback to ensure that the XHCI stack is properly
shutdown in reboot/shutdown path.

In kexec flow, kernel_restart_prepare() performs actions necessary
to prepare the system for a restart and invokes device_shutdown. To
ensure proper shutdown attach the dwc3 shutdown implementation which
mirrors the remove method.

$ kexec -e

<snip>
xhci-hcd xhci-hcd.0.auto: remove, state 1
usb usb1: USB disconnect, device number 1
usb 1-1: USB disconnect, device number 6
xhci-hcd xhci-hcd.0.auto: USB bus 1 deregistered
kexec_core: Starting new kernel

Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
---
Referred implementation from mainline commit ' 85e8a23936ab
("scsi: lpfc: Add shutdown method for kexec").
---
 drivers/usb/dwc3/dwc3-xilinx.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/dwc3/dwc3-xilinx.c b/drivers/usb/dwc3/dwc3-xilinx.c
index 4ca7f6240d07..09c3c5c226ab 100644
--- a/drivers/usb/dwc3/dwc3-xilinx.c
+++ b/drivers/usb/dwc3/dwc3-xilinx.c

@@ -422,6 +422,7 @@ static const struct dev_pm_ops dwc3_xlnx_dev_pm_ops = {
 static struct platform_driver dwc3_xlnx_driver = {
 	.probe		= dwc3_xlnx_probe,
 	.remove		= dwc3_xlnx_remove,
+	.shutdown	= dwc3_xlnx_remove,
 	.driver		= {
 		.name		= "dwc3-xilinx",
 		.of_match_table	= dwc3_xlnx_of_match,

base-commit: a0bea9e39035edc56a994630e6048c8a191a99d8
-- 
2.34.1