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/usb/wusbcore/wusbhc.c b/drivers/usb/wusbcore/wusbhc.c
index e712af3..742c607 100644
--- a/drivers/usb/wusbcore/wusbhc.c
+++ b/drivers/usb/wusbcore/wusbhc.c
@@ -325,13 +325,7 @@
goto error_create_attr_group;
}
- result = wusbhc_pal_register(wusbhc);
- if (result < 0)
- goto error_pal_register;
return 0;
-
-error_pal_register:
- sysfs_remove_group(wusbhc_kobj(wusbhc), &wusbhc_attr_group);
error_create_attr_group:
return result;
}
@@ -457,7 +451,8 @@
*/
void wusbhc_reset_all(struct wusbhc *wusbhc)
{
- uwb_rc_reset_all(wusbhc->uwb_rc);
+ if (wusbhc->uwb_rc)
+ uwb_rc_reset_all(wusbhc->uwb_rc);
}
EXPORT_SYMBOL_GPL(wusbhc_reset_all);