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2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c

 kernel/drivers/usb/core/generic.c
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@@ -21,6 +21,7 @@
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 #include <linux/usb.h>
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 #include <linux/usb/hcd.h>
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+#include <uapi/linux/usb/audio.h>
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 #include "usb.h"
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 static inline const char *plural(int n)
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@@ -42,34 +43,14 @@
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 		&& desc->bInterfaceProtocol == 1;
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 }
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-static int get_usb_audio_config(struct usb_host_bos *bos)
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+static bool is_audio(struct usb_interface_descriptor *desc)
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 {
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-	unsigned int desc_cnt, num_cfg_desc, len = 0;
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-	unsigned char *buffer;
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-	struct usb_config_summary_descriptor *conf_summary;
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+	return desc->bInterfaceClass == USB_CLASS_AUDIO;
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+}
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-	if (!bos || !bos->config_summary)
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-		goto done;
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-
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-	num_cfg_desc = bos->num_config_summary_desc;
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-	conf_summary = bos->config_summary;
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-	buffer = (unsigned char *)conf_summary;
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-	for (desc_cnt = 0; desc_cnt < num_cfg_desc; desc_cnt++) {
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-		conf_summary =
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-			(struct usb_config_summary_descriptor *)(buffer + len);
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-
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-		len += conf_summary->bLength;
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-
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-		if (conf_summary->bcdVersion != USB_CONFIG_SUMMARY_DESC_REV ||
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-				conf_summary->bClass != USB_CLASS_AUDIO)
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-			continue;
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-
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-		/* return 1st config as per device preference */
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-		return conf_summary->bConfigurationIndex[0];
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-	}
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-
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-done:
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-	return -EINVAL;
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+static bool is_uac3_config(struct usb_interface_descriptor *desc)
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+{
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+	return desc->bInterfaceProtocol == UAC_VERSION_3;
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 }
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 int usb_choose_configuration(struct usb_device *udev)
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@@ -137,6 +118,31 @@
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 			continue;
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 		}
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+		/*
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+		 * Select first configuration as default for audio so that
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+		 * devices that don't comply with UAC3 protocol are supported.
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+		 * But, still iterate through other configurations and
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+		 * select UAC3 compliant config if present.
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+		 */
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+		if (desc && is_audio(desc)) {
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+			/* Always prefer the first found UAC3 config */
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+			if (is_uac3_config(desc)) {
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+				best = c;
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+				break;
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+			}
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+
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+			/* If there is no UAC3 config, prefer the first config */
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+			else if (i == 0)
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+				best = c;
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+
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+			/* Unconditional continue, because the rest of the code
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+			 * in the loop is irrelevant for audio devices, and
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+			 * because it can reassign best, which for audio devices
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+			 * we don't want.
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+			 */
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+			continue;
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+		}
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+
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 		/* When the first config's first interface is one of Microsoft's
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 		 * pet nonstandard Ethernet-over-USB protocols, ignore it unless
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 		 * this kernel has enabled the necessary host side driver.
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@@ -175,10 +181,7 @@
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 			insufficient_power, plural(insufficient_power));
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 	if (best) {
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-		/* choose device preferred config */
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-		i = get_usb_audio_config(udev->bos);
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-		if (i < 0)
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-			i = best->desc.bConfigurationValue;
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+		i = best->desc.bConfigurationValue;
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 		dev_dbg(&udev->dev,
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 			"configuration #%d chosen from %d choice%s\n",
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 			i, num_configs, plural(num_configs));
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@@ -192,7 +195,35 @@
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 }
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 EXPORT_SYMBOL_GPL(usb_choose_configuration);
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-static int generic_probe(struct usb_device *udev)
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+static int __check_for_non_generic_match(struct device_driver *drv, void *data)
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+{
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+	struct usb_device *udev = data;
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+	struct usb_device_driver *udrv;
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+
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+	if (!is_usb_device_driver(drv))
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+		return 0;
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+	udrv = to_usb_device_driver(drv);
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+	if (udrv == &usb_generic_driver)
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+		return 0;
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+	return usb_driver_applicable(udev, udrv);
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+}
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+
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+static bool usb_generic_driver_match(struct usb_device *udev)
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+{
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+	if (udev->use_generic_driver)
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+		return true;
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+
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+	/*
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+	 * If any other driver wants the device, leave the device to this other
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+	 * driver.
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+	 */
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+	if (bus_for_each_drv(&usb_bus_type, NULL, udev, __check_for_non_generic_match))
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+		return false;
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+
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+	return true;
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+}
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+
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+int usb_generic_driver_probe(struct usb_device *udev)
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 {
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 	int err, c;
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@@ -219,7 +250,7 @@
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 	return 0;
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 }
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-static void generic_disconnect(struct usb_device *udev)
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+void usb_generic_driver_disconnect(struct usb_device *udev)
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 {
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 	usb_notify_remove_device(udev);
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@@ -231,7 +262,7 @@
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 #ifdef	CONFIG_PM
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-static int generic_suspend(struct usb_device *udev, pm_message_t msg)
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+int usb_generic_driver_suspend(struct usb_device *udev, pm_message_t msg)
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 {
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 	int rc;
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@@ -254,10 +285,12 @@
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 	else
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 		rc = usb_port_suspend(udev, msg);
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+	if (rc == 0)
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+		usbfs_notify_suspend(udev);
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 	return rc;
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 }
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-static int generic_resume(struct usb_device *udev, pm_message_t msg)
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+int usb_generic_driver_resume(struct usb_device *udev, pm_message_t msg)
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 {
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 	int rc;
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@@ -270,6 +303,9 @@
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 		rc = hcd_bus_resume(udev, msg);
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 	else
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 		rc = usb_port_resume(udev, msg);
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+
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+	if (rc == 0)
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+		usbfs_notify_resume(udev);
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 	return rc;
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 }
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@@ -277,11 +313,12 @@
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 struct usb_device_driver usb_generic_driver = {
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 	.name =	"usb",
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-	.probe = generic_probe,
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-	.disconnect = generic_disconnect,
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+	.match = usb_generic_driver_match,
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+	.probe = usb_generic_driver_probe,
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+	.disconnect = usb_generic_driver_disconnect,
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 #ifdef	CONFIG_PM
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-	.suspend = generic_suspend,
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-	.resume = generic_resume,
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+	.suspend = usb_generic_driver_suspend,
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+	.resume = usb_generic_driver_resume,
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 #endif
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 	.supports_autosuspend = 1,
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 };