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authorBastien Nocera <hadess@hadess.net>2020-08-18 14:04:45 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-08-18 14:09:31 +0300
commitd5643d2249b279077427b2c2b2ffae9b70c95b0b (patch)
treec46c848efde4943fe5629a6ca3bd5aad6ab8908d /drivers/usb
parentadb6e6ac20eedcf1dce19dc75b224e63c0828ea1 (diff)
downloadlinux-d5643d2249b279077427b2c2b2ffae9b70c95b0b.tar.xz
USB: Fix device driver race
When a new device with a specialised device driver is plugged in, the new driver will be modprobe()'d but the driver core will attach the "generic" driver to the device. After that, nothing will trigger a reprobe when the modprobe()'d device driver has finished initialising, as the device has the "generic" driver attached to it. Trigger a reprobe ourselves when new specialised drivers get registered. Fixes: 88b7381a939d ("USB: Select better matching USB drivers when available") Signed-off-by: Bastien Nocera <hadess@hadess.net> Cc: stable <stable@vger.kernel.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/20200818110445.509668-3-hadess@hadess.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/core/driver.c40
1 files changed, 38 insertions, 2 deletions
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index f81606c6a35b..7e73e989645b 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -905,6 +905,35 @@ static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
return 0;
}
+static bool is_dev_usb_generic_driver(struct device *dev)
+{
+ struct usb_device_driver *udd = dev->driver ?
+ to_usb_device_driver(dev->driver) : NULL;
+
+ return udd == &usb_generic_driver;
+}
+
+static int __usb_bus_reprobe_drivers(struct device *dev, void *data)
+{
+ struct usb_device_driver *new_udriver = data;
+ struct usb_device *udev;
+ int ret;
+
+ if (!is_dev_usb_generic_driver(dev))
+ return 0;
+
+ udev = to_usb_device(dev);
+ if (usb_device_match_id(udev, new_udriver->id_table) == NULL &&
+ (!new_udriver->match || new_udriver->match(udev) != 0))
+ return 0;
+
+ ret = device_reprobe(dev);
+ if (ret && ret != -EPROBE_DEFER)
+ dev_err(dev, "Failed to reprobe device (error %d)\n", ret);
+
+ return 0;
+}
+
/**
* usb_register_device_driver - register a USB device (not interface) driver
* @new_udriver: USB operations for the device driver
@@ -934,13 +963,20 @@ int usb_register_device_driver(struct usb_device_driver *new_udriver,
retval = driver_register(&new_udriver->drvwrap.driver);
- if (!retval)
+ if (!retval) {
pr_info("%s: registered new device driver %s\n",
usbcore_name, new_udriver->name);
- else
+ /*
+ * Check whether any device could be better served with
+ * this new driver
+ */
+ bus_for_each_dev(&usb_bus_type, NULL, new_udriver,
+ __usb_bus_reprobe_drivers);
+ } else {
printk(KERN_ERR "%s: error %d registering device "
" driver %s\n",
usbcore_name, retval, new_udriver->name);
+ }
return retval;
}