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@xxxxxxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
---
Changes since v7:
- None
Changes since v6:
- Added Alan's ack
Changes since v5:
- Throw error when device_reprobe() fails
Changes since v4:
- Add commit subject to "fixes" section
- Clarify conditional that checks for generic driver
- Remove check duplicated inside the loop
Changes since v3:
- Only reprobe devices that could use the new driver
- Many code fixes
Changes since v2:
- Fix formatting
Changes since v1:
- Simplified after Alan Stern's comments and some clarifications from
Benjamin Tissoires.
drivers/usb/core/driver.c | 40 +++++++++++++++++++++++++++++++++++++--
1 file 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;
}
--
2.26.2
