1 files changed, 89 insertions, 37 deletions

diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c
index f713cecc1f41..a48994e11ef3 100644
--- a/drivers/usb/core/generic.c
+++ b/drivers/usb/core/generic.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * drivers/usb/generic.c - generic driver for USB devices (not interfaces)
+ * drivers/usb/core/generic.c - generic driver for USB devices (not interfaces)
  *
  * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de>
  *
@@ -21,14 +21,10 @@
 
 #include <linux/usb.h>
 #include <linux/usb/hcd.h>
+#include <linux/string_choices.h>
 #include <uapi/linux/usb/audio.h>
 #include "usb.h"
 
-static inline const char *plural(int n)
-{
-	return (n == 1 ? "" : "s");
-}
-
 static int is_rndis(struct usb_interface_descriptor *desc)
 {
 	return desc->bInterfaceClass == USB_CLASS_COMM
@@ -59,10 +55,26 @@ int usb_choose_configuration(struct usb_device *udev)
 	int num_configs;
 	int insufficient_power = 0;
 	struct usb_host_config *c, *best;
+	struct usb_device_driver *udriver;
+
+	/*
+	 * If a USB device (not an interface) doesn't have a driver then the
+	 * kernel has no business trying to select or install a configuration
+	 * for it.
+	 */
+	if (!udev->dev.driver)
+		return -1;
+	udriver = to_usb_device_driver(udev->dev.driver);
 
 	if (usb_device_is_owned(udev))
 		return 0;
 
+	if (udriver->choose_configuration) {
+		i = udriver->choose_configuration(udev);
+		if (i >= 0)
+			return i;
+	}
+
 	best = NULL;
 	c = udev->config;
 	num_configs = udev->descriptor.bNumConfigurations;
@@ -118,6 +130,31 @@ int usb_choose_configuration(struct usb_device *udev)
 			continue;
 		}
 
+		/*
+		 * Select first configuration as default for audio so that
+		 * devices that don't comply with UAC3 protocol are supported.
+		 * But, still iterate through other configurations and
+		 * select UAC3 compliant config if present.
+		 */
+		if (desc && is_audio(desc)) {
+			/* Always prefer the first found UAC3 config */
+			if (is_uac3_config(desc)) {
+				best = c;
+				break;
+			}
+
+			/* If there is no UAC3 config, prefer the first config */
+			else if (i == 0)
+				best = c;
+
+			/* Unconditional continue, because the rest of the code
+			 * in the loop is irrelevant for audio devices, and
+			 * because it can reassign best, which for audio devices
+			 * we don't want.
+			 */
+			continue;
+		}
+
 		/* When the first config's first interface is one of Microsoft's
 		 * pet nonstandard Ethernet-over-USB protocols, ignore it unless
 		 * this kernel has enabled the necessary host side driver.
@@ -132,25 +169,6 @@ int usb_choose_configuration(struct usb_device *udev)
 #endif
 		}
 
-		/*
-		 * Select first configuration as default for audio so that
-		 * devices that don't comply with UAC3 protocol are supported.
-		 * But, still iterate through other configurations and
-		 * select UAC3 compliant config if present.
-		 */
-		if (i == 0 && num_configs > 1 && desc && is_audio(desc)) {
-			best = c;
-			continue;
-		}
-
-		if (i > 0 && desc && is_audio(desc)) {
-			if (is_uac3_config(desc)) {
-				best = c;
-				break;
-			}
-			continue;
-		}
-
 		/* From the remaining configs, choose the first one whose
 		 * first interface is for a non-vendor-specific class.
 		 * Reason: Linux is more likely to have a class driver
@@ -172,24 +190,52 @@ int usb_choose_configuration(struct usb_device *udev)
 	if (insufficient_power > 0)
 		dev_info(&udev->dev, "rejected %d configuration%s "
 			"due to insufficient available bus power\n",
-			insufficient_power, plural(insufficient_power));
+			insufficient_power, str_plural(insufficient_power));
 
 	if (best) {
 		i = best->desc.bConfigurationValue;
 		dev_dbg(&udev->dev,
 			"configuration #%d chosen from %d choice%s\n",
-			i, num_configs, plural(num_configs));
+			i, num_configs, str_plural(num_configs));
 	} else {
 		i = -1;
 		dev_warn(&udev->dev,
 			"no configuration chosen from %d choice%s\n",
-			num_configs, plural(num_configs));
+			num_configs, str_plural(num_configs));
 	}
 	return i;
 }
 EXPORT_SYMBOL_GPL(usb_choose_configuration);
 
-static int generic_probe(struct usb_device *udev)
+static int __check_for_non_generic_match(struct device_driver *drv, void *data)
+{
+	struct usb_device *udev = data;
+	struct usb_device_driver *udrv;
+
+	if (!is_usb_device_driver(drv))
+		return 0;
+	udrv = to_usb_device_driver(drv);
+	if (udrv == &usb_generic_driver)
+		return 0;
+	return usb_driver_applicable(udev, udrv);
+}
+
+static bool usb_generic_driver_match(struct usb_device *udev)
+{
+	if (udev->use_generic_driver)
+		return true;
+
+	/*
+	 * If any other driver wants the device, leave the device to this other
+	 * driver.
+	 */
+	if (bus_for_each_drv(&usb_bus_type, NULL, udev, __check_for_non_generic_match))
+		return false;
+
+	return true;
+}
+
+int usb_generic_driver_probe(struct usb_device *udev)
 {
 	int err, c;
 
@@ -197,7 +243,7 @@ static int generic_probe(struct usb_device *udev)
 	 * with the driver core and lets interface drivers bind to them.
 	 */
 	if (udev->authorized == 0)
-		dev_err(&udev->dev, "Device is not authorized for usage\n");
+		dev_info(&udev->dev, "Device is not authorized for usage\n");
 	else {
 		c = usb_choose_configuration(udev);
 		if (c >= 0) {
@@ -216,7 +262,7 @@ static int generic_probe(struct usb_device *udev)
 	return 0;
 }
 
-static void generic_disconnect(struct usb_device *udev)
+void usb_generic_driver_disconnect(struct usb_device *udev)
 {
 	usb_notify_remove_device(udev);
 
@@ -228,7 +274,7 @@ static void generic_disconnect(struct usb_device *udev)
 
 #ifdef	CONFIG_PM
 
-static int generic_suspend(struct usb_device *udev, pm_message_t msg)
+int usb_generic_driver_suspend(struct usb_device *udev, pm_message_t msg)
 {
 	int rc;
 
@@ -251,10 +297,12 @@ static int generic_suspend(struct usb_device *udev, pm_message_t msg)
 	else
 		rc = usb_port_suspend(udev, msg);
 
+	if (rc == 0)
+		usbfs_notify_suspend(udev);
 	return rc;
 }
 
-static int generic_resume(struct usb_device *udev, pm_message_t msg)
+int usb_generic_driver_resume(struct usb_device *udev, pm_message_t msg)
 {
 	int rc;
 
@@ -267,6 +315,9 @@ static int generic_resume(struct usb_device *udev, pm_message_t msg)
 		rc = hcd_bus_resume(udev, msg);
 	else
 		rc = usb_port_resume(udev, msg);
+
+	if (rc == 0)
+		usbfs_notify_resume(udev);
 	return rc;
 }
 
@@ -274,11 +325,12 @@ static int generic_resume(struct usb_device *udev, pm_message_t msg)
 
 struct usb_device_driver usb_generic_driver = {
 	.name =	"usb",
-	.probe = generic_probe,
-	.disconnect = generic_disconnect,
+	.match = usb_generic_driver_match,
+	.probe = usb_generic_driver_probe,
+	.disconnect = usb_generic_driver_disconnect,
 #ifdef	CONFIG_PM
-	.suspend = generic_suspend,
-	.resume = generic_resume,
+	.suspend = usb_generic_driver_suspend,
+	.resume = usb_generic_driver_resume,
 #endif
 	.supports_autosuspend = 1,
 };