From: Zhu Yi <yi.zhu@xxxxxxxxx>
The patch adds a mutex to protect the iwm_reset_worker against netdev
ndo_open and ndo_stop because all of them call iwm_up and iwm_down in
the implementation. Note the latter two are already protected by
rtnl. So if iwm_reset_worker is not required in the future, the mutex
can also be removed.
Signed-off-by: Zhu Yi <yi.zhu@xxxxxxxxx>
Signed-off-by: Samuel Ortiz <samuel.ortiz@xxxxxxxxx>
---
drivers/net/wireless/iwmc3200wifi/iwm.h | 1 +
drivers/net/wireless/iwmc3200wifi/main.c | 54 ++++++++++++++++++++++++++---
2 files changed, 49 insertions(+), 6 deletions(-)
diff --git a/drivers/net/wireless/iwmc3200wifi/iwm.h b/drivers/net/wireless/iwmc3200wifi/iwm.h
index 4aa0ad1..77c339f 100644
--- a/drivers/net/wireless/iwmc3200wifi/iwm.h
+++ b/drivers/net/wireless/iwmc3200wifi/iwm.h
@@ -288,6 +288,7 @@ struct iwm_priv {
u8 *eeprom;
struct timer_list watchdog;
struct work_struct reset_worker;
+ struct mutex mutex;
struct rfkill *rfkill;
char private[0] __attribute__((__aligned__(NETDEV_ALIGN)));
diff --git a/drivers/net/wireless/iwmc3200wifi/main.c b/drivers/net/wireless/iwmc3200wifi/main.c
index 4d3c423..8be206d 100644
--- a/drivers/net/wireless/iwmc3200wifi/main.c
+++ b/drivers/net/wireless/iwmc3200wifi/main.c
@@ -112,6 +112,9 @@ static void iwm_statistics_request(struct work_struct *work)
iwm_send_umac_stats_req(iwm, 0);
}
+int __iwm_up(struct iwm_priv *iwm);
+int __iwm_down(struct iwm_priv *iwm);
+
static void iwm_reset_worker(struct work_struct *work)
{
struct iwm_priv *iwm;
@@ -120,6 +123,19 @@ static void iwm_reset_worker(struct work_struct *work)
iwm = container_of(work, struct iwm_priv, reset_worker);
+ /*
+ * XXX: The iwm->mutex is introduced purely for this reset work,
+ * because the other users for iwm_up and iwm_down are only netdev
+ * ndo_open and ndo_stop which are already protected by rtnl.
+ * Please remove iwm->mutex together if iwm_reset_worker() is not
+ * required in the future.
+ */
+ if (!mutex_trylock(&iwm->mutex)) {
+ IWM_WARN(iwm, "We are in the middle of interface bringing "
+ "UP/DOWN. Skip driver resetting.\n");
+ return;
+ }
+
if (iwm->umac_profile_active) {
profile = kmalloc(sizeof(struct iwm_umac_profile), GFP_KERNEL);
if (profile)
@@ -128,10 +144,10 @@ static void iwm_reset_worker(struct work_struct *work)
IWM_ERR(iwm, "Couldn't alloc memory for profile\n");
}
- iwm_down(iwm);
+ __iwm_down(iwm);
while (retry++ < 3) {
- ret = iwm_up(iwm);
+ ret = __iwm_up(iwm);
if (!ret)
break;
@@ -142,7 +158,7 @@ static void iwm_reset_worker(struct work_struct *work)
IWM_WARN(iwm, "iwm_up() failed: %d\n", ret);
kfree(profile);
- return;
+ goto out;
}
if (profile) {
@@ -151,6 +167,9 @@ static void iwm_reset_worker(struct work_struct *work)
iwm_send_mlme_profile(iwm);
kfree(profile);
}
+
+ out:
+ mutex_unlock(&iwm->mutex);
}
static void iwm_watchdog(unsigned long data)
@@ -215,6 +234,7 @@ int iwm_priv_init(struct iwm_priv *iwm)
init_timer(&iwm->watchdog);
iwm->watchdog.function = iwm_watchdog;
iwm->watchdog.data = (unsigned long)iwm;
+ mutex_init(&iwm->mutex);
return 0;
}
@@ -476,7 +496,7 @@ void iwm_link_off(struct iwm_priv *iwm)
iwm_rx_free(iwm);
- cancel_delayed_work(&iwm->stats_request);
+ cancel_delayed_work_sync(&iwm->stats_request);
memset(wstats, 0, sizeof(struct iw_statistics));
wstats->qual.updated = IW_QUAL_ALL_INVALID;
@@ -521,7 +541,7 @@ static int iwm_channels_init(struct iwm_priv *iwm)
return 0;
}
-int iwm_up(struct iwm_priv *iwm)
+int __iwm_up(struct iwm_priv *iwm)
{
int ret;
struct iwm_notif *notif_reboot, *notif_ack = NULL;
@@ -657,7 +677,18 @@ int iwm_up(struct iwm_priv *iwm)
return -EIO;
}
-int iwm_down(struct iwm_priv *iwm)
+int iwm_up(struct iwm_priv *iwm)
+{
+ int ret;
+
+ mutex_lock(&iwm->mutex);
+ ret = __iwm_up(iwm);
+ mutex_unlock(&iwm->mutex);
+
+ return ret;
+}
+
+int __iwm_down(struct iwm_priv *iwm)
{
int ret;
@@ -688,3 +719,14 @@ int iwm_down(struct iwm_priv *iwm)
return 0;
}
+
+int iwm_down(struct iwm_priv *iwm)
+{
+ int ret;
+
+ mutex_lock(&iwm->mutex);
+ ret = __iwm_down(iwm);
+ mutex_unlock(&iwm->mutex);
+
+ return ret;
+}
--
1.6.3.1
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