[RFC PATCH v2 03/17] gpu: host1x: Show number of pending waiters in debugfs

[Mikko Perttunen]

Show the number of pending waiters in the debugfs status file.
This is useful for testing to verify that waiters do not leak
or accumulate incorrectly.

Signed-off-by: Mikko Perttunen <mperttunen at nvidia.com>
---
 drivers/gpu/host1x/debug.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/host1x/debug.c b/drivers/gpu/host1x/debug.c
index 3eee4318b158..2d06a7406b3b 100644
--- a/drivers/gpu/host1x/debug.c
+++ b/drivers/gpu/host1x/debug.c
@@ -69,6 +69,7 @@ static int show_channel(struct host1x_channel *ch, void *data, bool show_fifo)
 
 static void show_syncpts(struct host1x *m, struct output *o)
 {
+	struct list_head *pos;
 	unsigned int i;
 
 	host1x_debug_output(o, "---- syncpts ----\n");
@@ -76,12 +77,19 @@ static void show_syncpts(struct host1x *m, struct output *o)
 	for (i = 0; i < host1x_syncpt_nb_pts(m); i++) {
 		u32 max = host1x_syncpt_read_max(m->syncpt + i);
 		u32 min = host1x_syncpt_load(m->syncpt + i);
+		unsigned int waiters = 0;
 
-		if (!min && !max)
+		spin_lock(&m->syncpt[i].intr.lock);
+		list_for_each(pos, &m->syncpt[i].intr.wait_head)
+			waiters++;
+		spin_unlock(&m->syncpt[i].intr.lock);
+
+		if (!min && !max && !waiters)
 			continue;
 
-		host1x_debug_output(o, "id %u (%s) min %d max %d\n",
-				    i, m->syncpt[i].name, min, max);
+		host1x_debug_output(o,
+				    "id %u (%s) min %d max %d (%d waiters)\n",
+				    i, m->syncpt[i].name, min, max, waiters);
 	}
 
 	for (i = 0; i < host1x_syncpt_nb_bases(m); i++) {
-- 
2.28.0