From: Ryan The manual driver <-> device binding attribute in sysfs doesn't return the correct value on failure or success of driver_probe_device. driver_probe_device returns 1 on success (the driver accepted the device) or 0 on probe failure (when the driver didn't accept the device but no real error occured). However, the attribute can't just return 0 or 1, it must return the number of bytes consumed from buf or an error value. Returning 0 indicates to userspace that nothing was written (even though the kernel has tried to do the bind/probe and failed). Returning 1 indicates that only one character was accepted in which case userspace will re-try the write with a partial string. A more correct version of driver_bind would return count (to indicate the entire string was consumed) when driver_probe_device returns 1 and -ENODEV when driver_probe_device returns 0. This patch makes that change. Signed-off-by: Ryan Wilson Cc: Greg KH Signed-off-by: Andrew Morton --- drivers/base/bus.c | 5 +++++ 1 files changed, 5 insertions(+) diff -puN drivers/base/bus.c~driver-core-driver_bind-attribute-returns-incorrect-value drivers/base/bus.c --- devel/drivers/base/bus.c~driver-core-driver_bind-attribute-returns-incorrect-value 2006-03-28 14:05:03.000000000 -0800 +++ devel-akpm/drivers/base/bus.c 2006-03-28 14:05:03.000000000 -0800 @@ -188,6 +188,11 @@ static ssize_t driver_bind(struct device up(&dev->sem); if (dev->parent) up(&dev->parent->sem); + + if (err > 0) /* success */ + err = count; + else if (err == 0) /* driver didn't accept device */ + err = -ENODEV; } put_device(dev); put_bus(bus); _