[PATCH 2/2] usb: xhci: add check_init_status hook support

[Ray Chi]

In general, xHCI didn't do anything for port initialization. However,
there are some requirement or limitation on various platforms, so
vendors need to do some error handlings if the device connected to a
broken USB accessory.

This patch also add the hook to xhci_driver_overrides so that vendors
can add their specific protection easily if needed.

Signed-off-by: Ray Chi <raychi@xxxxxxxxxx>
---
 drivers/usb/host/xhci.c | 17 +++++++++++++++++
 drivers/usb/host/xhci.h |  1 +
 2 files changed, 18 insertions(+)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 65858f607437..f237af9d6e2e 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4358,6 +4358,20 @@ static int xhci_enable_device(struct usb_hcd *hcd, struct usb_device *udev)
 	return xhci_setup_device(hcd, udev, SETUP_CONTEXT_ONLY);
 }
 
+/*
+ * The function could get the status of port initialization.
+ */
+static int xhci_check_init_status(struct usb_hcd *hcd, struct usb_device *udev, int r)
+{
+	/*
+	 * In general, this function is not necessory. Some platforms may
+	 * need doing error handling when the port initialization takes a
+	 * long time to do. The device can use the override callback to
+	 * do specific handlings.
+	 */
+	return 0;
+}
+
 /*
  * Transfer the port index into real index in the HW port status
  * registers. Caculate offset between the port's PORTSC register
@@ -5455,6 +5469,7 @@ static const struct hc_driver xhci_hc_driver = {
 	.enable_device =	xhci_enable_device,
 	.update_hub_device =	xhci_update_hub_device,
 	.reset_device =		xhci_discover_or_reset_device,
+	.check_init_status =	xhci_check_init_status,
 
 	/*
 	 * scheduling support
@@ -5503,6 +5518,8 @@ void xhci_init_driver(struct hc_driver *drv,
 			drv->check_bandwidth = over->check_bandwidth;
 		if (over->reset_bandwidth)
 			drv->reset_bandwidth = over->reset_bandwidth;
+		if (over->check_init_status)
+			drv->check_init_status = over->check_init_status;
 	}
 }
 EXPORT_SYMBOL_GPL(xhci_init_driver);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 1960b47acfb2..33ce873236e9 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1944,6 +1944,7 @@ struct xhci_driver_overrides {
 			     struct usb_host_endpoint *ep);
 	int (*check_bandwidth)(struct usb_hcd *, struct usb_device *);
 	void (*reset_bandwidth)(struct usb_hcd *, struct usb_device *);
+	int (*check_init_status)(struct usb_hcd *hcd, struct usb_device *udev, int r);
 };
 
 #define	XHCI_CFC_DELAY		10
-- 
2.37.1.595.g718a3a8f04-goog