Patch "wifi: ath9k: fix AR9003 mac hardware hang check register offset calculation" has been added to the 4.19-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    wifi: ath9k: fix AR9003 mac hardware hang check register offset calculation

to the 4.19-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     wifi-ath9k-fix-ar9003-mac-hardware-hang-check-regist.patch
and it can be found in the queue-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 16cb131de7a54b775ccf43c5fa130d76ee3a1901
Author: Peter Seiderer <ps.report@xxxxxxx>
Date:   Wed Apr 26 17:35:00 2023 +0300

    wifi: ath9k: fix AR9003 mac hardware hang check register offset calculation
    
    [ Upstream commit 3e56c80931c7615250fe4bf83f93b57881969266 ]
    
    Fix ath9k_hw_verify_hang()/ar9003_hw_detect_mac_hang() register offset
    calculation (do not overflow the shift for the second register/queues
    above five, use the register layout described in the comments above
    ath9k_hw_verify_hang() instead).
    
    Fixes: 222e04830ff0 ("ath9k: Fix MAC HW hang check for AR9003")
    
    Reported-by: Gregg Wonderly <greggwonderly@xxxxxxxxxxxxxx>
    Link: https://lore.kernel.org/linux-wireless/E3A9C354-0CB7-420C-ADEF-F0177FB722F4@xxxxxxxxxxxxxx/
    Signed-off-by: Peter Seiderer <ps.report@xxxxxxx>
    Acked-by: Toke Høiland-Jørgensen <toke@xxxxxxx>
    Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
    Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20230422212423.26065-1-ps.report@xxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/wireless/ath/ath9k/ar9003_hw.c b/drivers/net/wireless/ath/ath9k/ar9003_hw.c
index 2fe12b0de5b4f..dea8a998fb622 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_hw.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_hw.c
@@ -1099,17 +1099,22 @@ static bool ath9k_hw_verify_hang(struct ath_hw *ah, unsigned int queue)
 {
 	u32 dma_dbg_chain, dma_dbg_complete;
 	u8 dcu_chain_state, dcu_complete_state;
+	unsigned int dbg_reg, reg_offset;
 	int i;
 
-	for (i = 0; i < NUM_STATUS_READS; i++) {
-		if (queue < 6)
-			dma_dbg_chain = REG_READ(ah, AR_DMADBG_4);
-		else
-			dma_dbg_chain = REG_READ(ah, AR_DMADBG_5);
+	if (queue < 6) {
+		dbg_reg = AR_DMADBG_4;
+		reg_offset = queue * 5;
+	} else {
+		dbg_reg = AR_DMADBG_5;
+		reg_offset = (queue - 6) * 5;
+	}
 
+	for (i = 0; i < NUM_STATUS_READS; i++) {
+		dma_dbg_chain = REG_READ(ah, dbg_reg);
 		dma_dbg_complete = REG_READ(ah, AR_DMADBG_6);
 
-		dcu_chain_state = (dma_dbg_chain >> (5 * queue)) & 0x1f;
+		dcu_chain_state = (dma_dbg_chain >> reg_offset) & 0x1f;
 		dcu_complete_state = dma_dbg_complete & 0x3;
 
 		if ((dcu_chain_state != 0x6) || (dcu_complete_state != 0x1))
@@ -1128,6 +1133,7 @@ static bool ar9003_hw_detect_mac_hang(struct ath_hw *ah)
 	u8 dcu_chain_state, dcu_complete_state;
 	bool dcu_wait_frdone = false;
 	unsigned long chk_dcu = 0;
+	unsigned int reg_offset;
 	unsigned int i = 0;
 
 	dma_dbg_4 = REG_READ(ah, AR_DMADBG_4);
@@ -1139,12 +1145,15 @@ static bool ar9003_hw_detect_mac_hang(struct ath_hw *ah)
 		goto exit;
 
 	for (i = 0; i < ATH9K_NUM_TX_QUEUES; i++) {
-		if (i < 6)
+		if (i < 6) {
 			chk_dbg = dma_dbg_4;
-		else
+			reg_offset = i * 5;
+		} else {
 			chk_dbg = dma_dbg_5;
+			reg_offset = (i - 6) * 5;
+		}
 
-		dcu_chain_state = (chk_dbg >> (5 * i)) & 0x1f;
+		dcu_chain_state = (chk_dbg >> reg_offset) & 0x1f;
 		if (dcu_chain_state == 0x6) {
 			dcu_wait_frdone = true;
 			chk_dcu |= BIT(i);