mac80211: add queue debugfs file

I suspect that some driver bugs can cause queues to be stopped while they shouldn't be, but it's hard to find out whether that is the case or not without having any visible information about the queues. This adds a file to debugfs that allows us to see the queues' statuses. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: add queue debugfs file
I suspect that some driver bugs can cause queues to be stopped while they shouldn't be, but it's hard to find out whether that is the case or not without having any visible information about the queues. This adds a file to debugfs that allows us to see the queues' statuses. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Johannes Berg · John W. Linville
1 parent 3b319aae42
Showing 2 changed files with 26 additions and 0 deletions Side-by-side Diff
net/mac80211/debugfs.c
net/mac80211/ieee80211_i.h
@@ -163,6 +163,29 @@
 	.open = mac80211_open_file_generic
 };
  
+static ssize_t queues_read(struct file *file, char __user *user_buf,
+			   size_t count, loff_t *ppos)
+{
+	struct ieee80211_local *local = file->private_data;
+	unsigned long flags;
+	char buf[IEEE80211_MAX_QUEUES * 20];
+	int q, res = 0;
+
+	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
+	for (q = 0; q < local->hw.queues; q++)
+		res += sprintf(buf + res, "%02d: %#.8lx/%d\n", q,
+				local->queue_stop_reasons[q],
+				__netif_subqueue_stopped(local->mdev, q));
+	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
+
+	return simple_read_from_buffer(user_buf, count, ppos, buf, res);
+}
+
+static const struct file_operations queues_ops = {
+	.read = queues_read,
+	.open = mac80211_open_file_generic
+};
+
 /* statistics stuff */
  
 #define DEBUGFS_STATS_FILE(name, buflen, fmt, value...)			\
@@ -298,6 +321,7 @@
 	DEBUGFS_ADD(total_ps_buffered);
 	DEBUGFS_ADD(wep_iv);
 	DEBUGFS_ADD(tsf);
+	DEBUGFS_ADD(queues);
 	DEBUGFS_ADD_MODE(reset, 0200);
 	DEBUGFS_ADD(noack);
  
@@ -350,6 +374,7 @@
 	DEBUGFS_DEL(total_ps_buffered);
 	DEBUGFS_DEL(wep_iv);
 	DEBUGFS_DEL(tsf);
+	DEBUGFS_DEL(queues);
 	DEBUGFS_DEL(reset);
 	DEBUGFS_DEL(noack);
  
@@ -783,6 +783,7 @@
 		struct dentry *total_ps_buffered;
 		struct dentry *wep_iv;
 		struct dentry *tsf;
+		struct dentry *queues;
 		struct dentry *reset;
 		struct dentry *noack;
 		struct dentry *statistics;
...	...	@@ -163,6 +163,29 @@
163	163	.open = mac80211_open_file_generic
164	164	};
165	165
	166	+static ssize_t queues_read(struct file file, char __user user_buf,
	167	+ size_t count, loff_t *ppos)
	168	+{
	169	+ struct ieee80211_local *local = file->private_data;
	170	+ unsigned long flags;
	171	+ char buf[IEEE80211_MAX_QUEUES * 20];
	172	+ int q, res = 0;
	173	+
	174	+ spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
	175	+ for (q = 0; q < local->hw.queues; q++)
	176	+ res += sprintf(buf + res, "%02d: %#.8lx/%d\n", q,
	177	+ local->queue_stop_reasons[q],
	178	+ __netif_subqueue_stopped(local->mdev, q));
	179	+ spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
	180	+
	181	+ return simple_read_from_buffer(user_buf, count, ppos, buf, res);
	182	+}
	183	+
	184	+static const struct file_operations queues_ops = {
	185	+ .read = queues_read,
	186	+ .open = mac80211_open_file_generic
	187	+};
	188	+
166	189	/* statistics stuff */
167	190
168	191	#define DEBUGFS_STATS_FILE(name, buflen, fmt, value...) \
...	...	@@ -298,6 +321,7 @@
298	321	DEBUGFS_ADD(total_ps_buffered);
299	322	DEBUGFS_ADD(wep_iv);
300	323	DEBUGFS_ADD(tsf);
	324	+ DEBUGFS_ADD(queues);
301	325	DEBUGFS_ADD_MODE(reset, 0200);
302	326	DEBUGFS_ADD(noack);
303	327
...	...	@@ -350,6 +374,7 @@
350	374	DEBUGFS_DEL(total_ps_buffered);
351	375	DEBUGFS_DEL(wep_iv);
352	376	DEBUGFS_DEL(tsf);
	377	+ DEBUGFS_DEL(queues);
353	378	DEBUGFS_DEL(reset);
354	379	DEBUGFS_DEL(noack);
355	380
...	...	@@ -783,6 +783,7 @@
783	783	struct dentry *total_ps_buffered;
784	784	struct dentry *wep_iv;
785	785	struct dentry *tsf;
	786	+ struct dentry *queues;
786	787	struct dentry *reset;
787	788	struct dentry *noack;
788	789	struct dentry *statistics;