[PATCH] ath10k: Free beacon buf later in vdev teardown.

From: greearb@candelatech.com
To: linux-wireless@vger.kernel.org
Cc: Ben Greear <greearb@candelatech.com>
Subject: [PATCH] ath10k:  Free beacon buf later in vdev teardown.
Date: Wed, 27 Feb 2019 08:27:56 -0800	[thread overview]
Message-ID: <20190227162756.13048-1-greearb@candelatech.com> (raw)

From: Ben Greear <greearb@candelatech.com>

My wave-1 firmware often crashes when I am bringing down
AP vdevs, and sometimes at least some machines lockup hard
after spewing IOMMU errors.

I don't see the same issue in STA mode, so I suspect beacons
are the issue.

Moving the beacon buf deletion to later in the vdev teardown
logic appears to help this problem.  Firmware still crashes
often, but several iterations did not show IOMMU errors and
machine didn't hang.

Signed-off-by: Ben Greear <greearb@candelatech.com>
---
 drivers/net/wireless/ath/ath10k/mac.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index f70c48ec9464..c38561788791 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -6142,10 +6142,6 @@ static void ath10k_remove_interface(struct ieee80211_hw *hw,
 
 	mutex_lock(&ar->conf_mutex);
 
-	spin_lock_bh(&ar->data_lock);
-	ath10k_mac_vif_beacon_cleanup(arvif);
-	spin_unlock_bh(&ar->data_lock);
-
 	ret = ath10k_spectral_vif_stop(arvif);
 	if (ret)
 		ath10k_warn(ar, "failed to stop spectral for vdev %i: %d\n",
@@ -6204,6 +6200,10 @@ static void ath10k_remove_interface(struct ieee80211_hw *hw,
 			peer->vif = NULL;
 		}
 	}
+
+	/* Clean this up late, less opportunity for firmware to access
+	   DMA memory we have deleted. */
+	ath10k_mac_vif_beacon_cleanup(arvif);
 	spin_unlock_bh(&ar->data_lock);
 
 	ath10k_peer_cleanup(ar, arvif->vdev_id);
-- 
2.20.1

