From a899575191ba85a71401f2c8f36bec7b14487043 Mon Sep 17 00:00:00 2001 From: Thomas Pugliese Date: Mon, 24 Jun 2013 14:26:35 -0500 Subject: 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 Signed-off-by: Greg Kroah-Hartman --- drivers/uwb/pal.c | 2 ++ drivers/uwb/uwb-internal.h | 3 ++- 2 files changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/uwb') diff --git a/drivers/uwb/pal.c b/drivers/uwb/pal.c index 8ee7d90a8c68..690577d2a35b 100644 --- a/drivers/uwb/pal.c +++ b/drivers/uwb/pal.c @@ -44,10 +44,12 @@ int uwb_pal_register(struct uwb_pal *pal) 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) { diff --git a/drivers/uwb/uwb-internal.h b/drivers/uwb/uwb-internal.h index a7494bf10081..9a103b100f1e 100644 --- a/drivers/uwb/uwb-internal.h +++ b/drivers/uwb/uwb-internal.h @@ -55,7 +55,8 @@ static inline struct uwb_rc *__uwb_rc_get(struct uwb_rc *rc) static inline void __uwb_rc_put(struct uwb_rc *rc) { - uwb_dev_put(&rc->uwb_dev); + if (rc) + uwb_dev_put(&rc->uwb_dev); } extern int uwb_rc_reset(struct uwb_rc *rc); -- cgit v1.2.3