[PATCH 4.19 045/191] ath10k: Correct the DMA direction for management tx buffers

From: Greg Kroah-Hartman
Date: Fri Feb 21 2020 - 03:18:40 EST

From: Rakesh Pillai <pillair@xxxxxxxxxxxxxx>

[ Upstream commit 6ba8b3b6bd772f575f7736c8fd893c6981fcce16 ]

The management packets, send to firmware via WMI, are
mapped using the direction DMA_TO_DEVICE. Currently in
case of wmi cleanup, these buffers are being unmapped
using an incorrect DMA direction. This can cause unwanted
behavior when the host driver is handling a restart
of the wlan firmware.

We might see a trace like below

[<ffffff8008098b18>] __dma_inv_area+0x28/0x58
[<ffffff8001176734>] ath10k_wmi_mgmt_tx_clean_up_pending+0x60/0xb0 [ath10k_core]
[<ffffff80088c7c50>] idr_for_each+0x78/0xe4
[<ffffff80011766a4>] ath10k_wmi_detach+0x4c/0x7c [ath10k_core]
[<ffffff8001163d7c>] ath10k_core_stop+0x58/0x68 [ath10k_core]
[<ffffff800114fb74>] ath10k_halt+0xec/0x13c [ath10k_core]
[<ffffff8001165110>] ath10k_core_restart+0x11c/0x1a8 [ath10k_core]
[<ffffff80080c36bc>] process_one_work+0x16c/0x31c

Fix the incorrect DMA direction during the wmi
management tx buffer cleanup.

Tested HW: WCN3990
Tested FW: WLAN.HL.3.1-00784-QCAHLSWMTPLZ-1

Fixes: dc405152bb6 ("ath10k: handle mgmt tx completion event")
Signed-off-by: Rakesh Pillai <pillair@xxxxxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
drivers/net/wireless/ath/ath10k/wmi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath10k/wmi.c b/drivers/net/wireless/ath/ath10k/wmi.c
index 0f6ff7a78e49d..3372dfa0deccf 100644
--- a/drivers/net/wireless/ath/ath10k/wmi.c
+++ b/drivers/net/wireless/ath/ath10k/wmi.c
@@ -9193,7 +9193,7 @@ static int ath10k_wmi_mgmt_tx_clean_up_pending(int msdu_id, void *ptr,

msdu = pkt_addr->vaddr;
dma_unmap_single(ar->dev, pkt_addr->paddr,
- msdu->len, DMA_FROM_DEVICE);
+ msdu->len, DMA_TO_DEVICE);
ieee80211_free_txskb(ar->hw, msdu);

return 0;