USB: HWA: fix device probe failure
This patch fixes a race condition that caused the HWA_HC interface probe
function to occasionally fail. The HWA_HC would attempt to register
itself with the HWA_RC by searching for a uwb_rc class device with the
same parent device ptr. If the probe function for the HWA_RC interface
had yet to run, the uwb_rc class device would not have been created
causing the look up to fail and the HWA_HC probe function to return an
error causing the device to be unusable.
The fix is for the HWA to delay registering with the HWA_RC until
receiving the command from userspace to start the wireless channel. It
is the responsibility of userspace to ensure that the uwb_rc class
device has been created before starting the HWA channel.
Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/uwb/pal.c b/drivers/uwb/pal.c
index 8ee7d90..690577d 100644
--- a/drivers/uwb/pal.c
+++ b/drivers/uwb/pal.c
@@ -44,10 +44,12 @@
int ret;
if (pal->device) {
+ /* create a link to the uwb_rc in the PAL device's directory. */
ret = sysfs_create_link(&pal->device->kobj,
&rc->uwb_dev.dev.kobj, "uwb_rc");
if (ret < 0)
return ret;
+ /* create a link to the PAL in the UWB device's directory. */
ret = sysfs_create_link(&rc->uwb_dev.dev.kobj,
&pal->device->kobj, pal->name);
if (ret < 0) {