[PATCH 4.19 075/219] ath10k: Correct error handling of dma_map_single()

[Greg Kroah-Hartman]

From: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>

[ Upstream commit d43810b2c1808ac865aa1a2a2c291644bf95345c ]

The return value of dma_map_single() should be checked for errors using
dma_mapping_error() and the skb has been dequeued so it needs to be
freed.

This was found when enabling CONFIG_DMA_API_DEBUG and it warned about the
missing dma_mapping_error() call.

Fixes: 1807da49733e ("ath10k: wmi: add management tx by reference support over wmi")
Reported-by: Niklas Cassel <niklas.cassel@xxxxxxxxxx>
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/wireless/ath/ath10k/mac.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index 174e0ce31c42..448e3a8c33a6 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -3844,8 +3844,10 @@ void ath10k_mgmt_over_wmi_tx_work(struct work_struct *work)
 			     ar->running_fw->fw_file.fw_features)) {
 			paddr = dma_map_single(ar->dev, skb->data,
 					       skb->len, DMA_TO_DEVICE);
-			if (!paddr)
+			if (dma_mapping_error(ar->dev, paddr)) {
+				ieee80211_free_txskb(ar->hw, skb);
 				continue;
+			}
 			ret = ath10k_wmi_mgmt_tx_send(ar, skb, paddr);
 			if (ret) {
 				ath10k_warn(ar, "failed to transmit management frame by ref via WMI: %d\n",
-- 
2.20.1