From: Ryan Wilson Date: Wed, 22 Mar 2006 21:26:25 +0000 (-0500) Subject: [PATCH] driver core: driver_bind attribute returns incorrect value X-Git-Tag: v2.6.17-rc2~33^2~2 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=372254018eb1b65ee69210d11686bfc65c8d84db;p=linux-2.6 [PATCH] driver core: driver_bind attribute returns incorrect value 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 Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 48718b7f4f..76656acd00 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -188,6 +188,11 @@ static ssize_t driver_bind(struct device_driver *drv, 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);