From 88b7381a939de0fa1f1b1629c56b03dca7077309 Mon Sep 17 00:00:00 2001 From: Bastien Nocera Date: Wed, 16 Oct 2019 11:39:31 +0200 Subject: [PATCH] USB: Select better matching USB drivers when available Now that USB device drivers can reuse code from the generic USB device driver, we need to make sure that they get selected rather than the generic driver. Add an id_table and match vfunc to the usb_device_driver struct, which will get used to select a better matching driver at ->probe time. This is a similar mechanism to that used in the HID drivers, with the generic driver being selected unless there's a better matching one found in the registered drivers (see hid_generic_match() in drivers/hid/hid-generic.c). Signed-off-by: Bastien Nocera Acked-by: Alan Stern Link: https://lore.kernel.org/r/20191016093933.693-5-hadess@hadess.net Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/driver.c | 15 +++++++++++++-- drivers/usb/core/generic.c | 29 +++++++++++++++++++++++++++++ include/linux/usb.h | 2 ++ 3 files changed, 44 insertions(+), 2 deletions(-) diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index 6978983..9d1502a 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -818,13 +818,24 @@ static int usb_device_match(struct device *dev, struct device_driver *drv) { /* devices and interfaces are handled separately */ if (is_usb_device(dev)) { + struct usb_device *udev; + struct usb_device_driver *udrv; /* interface drivers never match devices */ if (!is_usb_device_driver(drv)) return 0; - /* TODO: Add real matching code */ - return 1; + udev = to_usb_device(dev); + udrv = to_usb_device_driver(drv); + + if (udrv->id_table && + usb_device_match_id(udev, udrv->id_table) != NULL) { + return 1; + } + + if (udrv->match) + return udrv->match(udev); + return 0; } else if (is_usb_interface(dev)) { struct usb_interface *intf; diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c index 28ece4d..84da85c 100644 --- a/drivers/usb/core/generic.c +++ b/drivers/usb/core/generic.c @@ -195,6 +195,34 @@ int usb_choose_configuration(struct usb_device *udev) } EXPORT_SYMBOL_GPL(usb_choose_configuration); +static int __check_usb_generic(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; + if (!udrv->id_table) + return 0; + + return usb_device_match_id(udev, udrv->id_table) != NULL; +} + +static bool usb_generic_driver_match(struct usb_device *udev) +{ + /* + * 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_usb_generic)) + return false; + + return true; +} + int usb_generic_driver_probe(struct usb_device *udev) { int err, c; @@ -285,6 +313,7 @@ int usb_generic_driver_resume(struct usb_device *udev, pm_message_t msg) struct usb_device_driver usb_generic_driver = { .name = "usb", + .match = usb_generic_driver_match, .probe = usb_generic_driver_probe, .disconnect = usb_generic_driver_disconnect, #ifdef CONFIG_PM diff --git a/include/linux/usb.h b/include/linux/usb.h index 94bd3b4..3663bd7 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1237,6 +1237,7 @@ struct usb_driver { struct usb_device_driver { const char *name; + bool (*match) (struct usb_device *udev); int (*probe) (struct usb_device *udev); void (*disconnect) (struct usb_device *udev); @@ -1244,6 +1245,7 @@ struct usb_device_driver { int (*resume) (struct usb_device *udev, pm_message_t message); const struct attribute_group **dev_groups; struct usbdrv_wrap drvwrap; + const struct usb_device_id *id_table; unsigned int supports_autosuspend:1; unsigned int generic_subclass:1; }; -- 2.7.4