[PATCH 101/379][SRU][OEM-5.6] ath11k: fix resource unavailability for htt stats after peer stats display

[You-Sheng Yang]

From: Sowmiya Sree Elavalagan <ssreeela at codeaurora.org>

BugLink: https://bugs.launchpad.net/bugs/1879633

htt stats are not working after htt peer stats display
and also after htt peer stats reset. Trying to dump htt
stats shows "Resource temporarily unavailable".
This is because of "ar->debug.htt_stats.stats_req" member is being
consecutively used for all htt stats without being reset
during the previous usage. Hence assigning NULL to this member
after freeing the allocated memory fixes the issue.

console logs below:
# echo 9 >/sys/kernel/debug/ath11k/ipq8074/mac1/htt_stats_type
# cat /sys/kernel/debug/ath11k/ipq8074/mac1/htt_stats_type
9
# cat /sys/kernel/debug/ath11k/ipq8074/mac1/htt_stats
cat: can't open '/sys/kernel/debug/ath11k/ipq8074/mac1/htt_stats'
: Resource temporarily unavailable

Signed-off-by: Sowmiya Sree Elavalagan <ssreeela at codeaurora.org>
Signed-off-by: Kalle Valo <kvalo at codeaurora.org>
Link: https://lore.kernel.org/r/1588592755-10427-1-git-send-email-ssreeela@codeaurora.org
(cherry picked from commit 52f274b519939f5e306b26f2a3cf7c63ef45c203)
Signed-off-by: You-Sheng Yang <vicamo.yang at canonical.com>
---
 drivers/net/wireless/ath/ath11k/debugfs_sta.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/net/wireless/ath/ath11k/debugfs_sta.c b/drivers/net/wireless/ath/ath11k/debugfs_sta.c
index 68963cfc5097..46eee5178f66 100644
--- a/drivers/net/wireless/ath/ath11k/debugfs_sta.c
+++ b/drivers/net/wireless/ath/ath11k/debugfs_sta.c
@@ -435,13 +435,22 @@ ath11k_dbg_sta_open_htt_peer_stats(struct inode *inode, struct file *file)
 	return 0;
 out:
 	vfree(stats_req);
+	ar->debug.htt_stats.stats_req = NULL;
 	return ret;
 }
 
 static int
 ath11k_dbg_sta_release_htt_peer_stats(struct inode *inode, struct file *file)
 {
+	struct ieee80211_sta *sta = inode->i_private;
+	struct ath11k_sta *arsta = (struct ath11k_sta *)sta->drv_priv;
+	struct ath11k *ar = arsta->arvif->ar;
+
+	mutex_lock(&ar->conf_mutex);
 	vfree(file->private_data);
+	ar->debug.htt_stats.stats_req = NULL;
+	mutex_unlock(&ar->conf_mutex);
+
 	return 0;
 }
 
-- 
2.29.2