cw1200: Driver hung detection and reporting

If there is a firmware exception or a bh error, report this to
the userspace. Userspace will then take care of handling this
event, e. g. by reloading the driver completely.

Category: bugfix
FIX=DMS01117799

ST-Ericsson ID: 401162
ST-Ericsson FOSS-OUT ID: NA

Change-Id: I74a8a434f9befbab66ff4cf6c5b5ce82a359c766
Signed-off-by: Vitaly Wool <vitaly.wool@sonyericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/44302
Reviewed-by: QATOOLS
Reviewed-by: Bartosz MARKOWSKI <bartosz.markowski@tieto.com>
Tested-by: Bartosz MARKOWSKI <bartosz.markowski@tieto.com>

3 files changed, 71 insertions, 12 deletions

diff --git a/drivers/staging/cw1200/bh.c b/drivers/staging/cw1200/bh.c
index 4b678f40c40..34bf7d733b8 100644
--- a/drivers/staging/cw1200/bh.c
+++ b/drivers/staging/cw1200/bh.c
@@ -549,6 +549,10 @@ tx:
 	if (!term) {
 		cw1200_dbg(CW1200_DBG_ERROR, "[BH] Fatal error, exitting.\n");
 		priv->bh_error = 1;
+#if defined(CONFIG_CW1200_USE_STE_EXTENSIONS)
+		ieee80211_driver_hang_notify(priv->vif, GFP_KERNEL);
+		cw1200_pm_stay_awake(&priv->pm_state, 3*HZ);
+#endif
 		/* TODO: schedule_work(recovery) */
 #ifndef HAS_PUT_TASK_STRUCT
 		/* The only reason of having this stupid code here is
diff --git a/drivers/staging/cw1200/debug.c b/drivers/staging/cw1200/debug.c
index 597f94de87f..2056101a3f4 100644
--- a/drivers/staging/cw1200/debug.c
+++ b/drivers/staging/cw1200/debug.c
@@ -426,6 +426,34 @@ static const struct file_operations fops_11n = {
 	.llseek = default_llseek,
 };
 
+#if defined(CONFIG_CW1200_USE_STE_EXTENSIONS)
+static ssize_t cw1200_hang_write(struct file *file,
+	const char __user *user_buf, size_t count, loff_t *ppos)
+{
+	struct cw1200_common *priv = file->private_data;
+	char buf[1];
+
+	if (!count)
+		return -EINVAL;
+	if (copy_from_user(buf, user_buf, 1))
+		return -EFAULT;
+
+	if (priv->vif) {
+		cw1200_pm_stay_awake(&priv->pm_state, 3*HZ);
+		ieee80211_driver_hang_notify(priv->vif, GFP_KERNEL);
+	} else
+		return -ENODEV;
+
+	return count;
+}
+
+static const struct file_operations fops_hang = {
+	.open = cw1200_generic_open,
+	.write = cw1200_hang_write,
+	.llseek = default_llseek,
+};
+#endif
+
 int cw1200_debug_init(struct cw1200_common *priv)
 {
 	struct cw1200_debug_priv *d = kzalloc(sizeof(struct cw1200_debug_priv),
@@ -451,6 +479,12 @@ int cw1200_debug_init(struct cw1200_common *priv)
 			d->debugfs_phy, priv, &fops_11n))
 		goto err;
 
+#if defined(CONFIG_CW1200_USE_STE_EXTENSIONS)
+	if (!debugfs_create_file("hang", S_IWUSR, d->debugfs_phy,
+			priv, &fops_hang))
+		goto err;
+#endif
+
 	return 0;
 
 err:
diff --git a/drivers/staging/cw1200/wsm.c b/drivers/staging/cw1200/wsm.c
index 5c52cdbb1c2..bb94d19da08 100644
--- a/drivers/staging/cw1200/wsm.c
+++ b/drivers/staging/cw1200/wsm.c
@@ -1083,9 +1083,15 @@ void wsm_lock_tx(struct cw1200_common *priv)
 {
 	wsm_cmd_lock(priv);
 	if (atomic_add_return(1, &priv->tx_lock) == 1) {
-		WARN_ON(wait_event_timeout(priv->bh_evt_wq,
-			!priv->hw_bufs_used, WSM_CMD_LAST_CHANCE_TIMEOUT) <= 0);
-		wsm_printk(KERN_DEBUG "[WSM] TX is locked.\n");
+		if (priv->bh_error) {
+			wsm_printk(KERN_ERR "fatal error occured, "
+					"could not take lock\n");
+		} else {
+			WARN_ON(wait_event_timeout(priv->bh_evt_wq,
+				!priv->hw_bufs_used,
+				WSM_CMD_LAST_CHANCE_TIMEOUT) <= 0);
+			wsm_printk(KERN_DEBUG "[WSM] TX is locked.\n");
+		}
 	}
 	wsm_cmd_unlock(priv);
 }
@@ -1098,20 +1104,29 @@ void wsm_lock_tx_async(struct cw1200_common *priv)
 
 void wsm_flush_tx(struct cw1200_common *priv)
 {
-	BUG_ON(!atomic_read(&priv->tx_lock));
-	WARN_ON(wait_event_timeout(priv->bh_evt_wq,
-		!priv->hw_bufs_used, WSM_CMD_LAST_CHANCE_TIMEOUT) <= 0);
+	if (priv->bh_error)
+		wsm_printk(KERN_ERR "fatal error occured, will not flush\n");
+	else {
+		BUG_ON(!atomic_read(&priv->tx_lock));
+		WARN_ON(wait_event_timeout(priv->bh_evt_wq,
+			!priv->hw_bufs_used,
+			WSM_CMD_LAST_CHANCE_TIMEOUT) <= 0);
+	}
 }
 
 void wsm_unlock_tx(struct cw1200_common *priv)
 {
 	int tx_lock;
-	tx_lock = atomic_sub_return(1, &priv->tx_lock);
-	if (tx_lock < 0) {
-		BUG_ON(1);
-	} else if (tx_lock == 0) {
-		cw1200_bh_wakeup(priv);
-		wsm_printk(KERN_DEBUG "[WSM] TX is unlocked.\n");
+	if (priv->bh_error)
+		wsm_printk(KERN_ERR "fatal error occured, unlock is unsafe\n");
+	else {
+		tx_lock = atomic_sub_return(1, &priv->tx_lock);
+		if (tx_lock < 0) {
+			BUG_ON(1);
+		} else if (tx_lock == 0) {
+			cw1200_bh_wakeup(priv);
+			wsm_printk(KERN_DEBUG "[WSM] TX is unlocked.\n");
+		}
 	}
 }
 
@@ -1133,6 +1148,12 @@ int wsm_handle_exception(struct cw1200_common *priv, u8 *data, size_t len)
 		"unknown error",
 	};
 
+#if defined(CONFIG_CW1200_USE_STE_EXTENSIONS)
+	/* Send the event upwards on the FW exception */
+	cw1200_pm_stay_awake(&priv->pm_state, 3*HZ);
+	ieee80211_driver_hang_notify(priv->vif, GFP_KERNEL);
+#endif
+
 	buf.begin = buf.data = data;
 	buf.end = &buf.begin[len];