From 245043dfc2101e7dc6268bf123b75305a91e4e00 Mon Sep 17 00:00:00 2001
Message-ID: <245043dfc2101e7dc6268bf123b75305a91e4e00.1782312080.git.lorenzo@kernel.org>
From: Wayen Yan <win847@gmail.com>
Date: Fri, 19 Jun 2026 21:12:06 +0800
Subject: [PATCH] net: airoha: Fix TX scheduler queue mask loop upper bound
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In airoha_qdma_set_chan_tx_sched(), the loop clearing queue mask was
using AIROHA_NUM_TX_RING (32) instead of AIROHA_NUM_QOS_QUEUES (8).

Each channel has 8 queues, and TXQ_DISABLE_CHAN_QUEUE_MASK(channel, i)
computes BIT(i + (channel * 8)). With i ranging 0..31, this causes:
- channel 0: clears bit 0..31 (all 4 channels) instead of 0..7
- channel 1: clears bit 8..31 (channels 1-3) instead of 8..15
- channel 2: clears bit 16..31 (channels 2-3) instead of 16..23
- channel 3: clears bit 24..31 (channel 3 only) - correct by accident

While BIT(32+) on arm64 produces 64-bit values truncated to 0 in u32
mask parameter, the loop still incorrectly clears queues within the
same channel beyond queue 7.

Even though this is functionally harmless (the register resets to 0
and is only ever cleared, never set — so clearing extra bits is a
no-op), the loop bound is semantically wrong and should be fixed for
correctness and clarity.

Fix by using AIROHA_NUM_QOS_QUEUES (8) as the loop upper bound.

Fixes: ef1ca9271313 ("net: airoha: Add sched HTB offload support")
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Wayen Yan <win847@gmail.com>
Link: https://patch.msgid.link/178187479434.2400840.1312143943526335838@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 drivers/net/ethernet/airoha/airoha_eth.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/airoha/airoha_eth.c
+++ b/drivers/net/ethernet/airoha/airoha_eth.c
@@ -2395,7 +2395,7 @@ static int airoha_qdma_set_chan_tx_sched
 	struct airoha_gdm_dev *dev = netdev_priv(netdev);
 	int i;
 
-	for (i = 0; i < AIROHA_NUM_TX_RING; i++)
+	for (i = 0; i < AIROHA_NUM_QOS_QUEUES; i++)
 		airoha_qdma_clear(dev->qdma, REG_QUEUE_CLOSE_CFG(channel),
 				  TXQ_DISABLE_CHAN_QUEUE_MASK(channel, i));
 
