From:   <sean.wang@mediatek.com>
To:     <marcel@holtmann.org>, <johan.hedberg@gmail.com>
CC:     <Mark-YW.Chen@mediatek.com>, <sean.wang@mediatek.com>,
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Subject: [PATCH 7/7] Bluetooth: btmtksdio: mask out interrupt status
Date:   Wed, 12 Jan 2022 15:39:17 +0800
Message-ID: <a8fb77540e15a0c042fdfa338bee32e992aaafc9.1641972745.git.objelf@gmail.com>
In-Reply-To: <bddfacd096b6fe927d08e48ad6993c17c9954028.1641972745.git.objelf@gmail.com>
References: <bddfacd096b6fe927d08e48ad6993c17c9954028.1641972745.git.objelf@gmail.com>
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From: Sean Wang <sean.wang@mediatek.com>

Currently, there is a loop in btmtksdio_txrx_work() which iteratively
executes until the variable int_status is zero.

But the variable int_status should be masked out with the actual interrupt
sources (MTK_REG_CHISR bit 0-15) before we check the loop condition.
Otherwise, RX_PKT_LEN (MTK_REG_CHISR bit 16-31) which is read-only and
unclearable would cause the loop to get stuck on some chipsets like
MT7663s.

Fixes: 26270bc189ea ("Bluetooth: btmtksdio: move interrupt service to work")
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
---
 drivers/bluetooth/btmtksdio.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/bluetooth/btmtksdio.c b/drivers/bluetooth/btmtksdio.c
index 491f029452ca..8be763ab3bf4 100644
--- a/drivers/bluetooth/btmtksdio.c
+++ b/drivers/bluetooth/btmtksdio.c
@@ -92,6 +92,7 @@ MODULE_DEVICE_TABLE(sdio, btmtksdio_table);
 #define TX_EMPTY		BIT(2)
 #define TX_FIFO_OVERFLOW	BIT(8)
 #define FW_MAILBOX_INT		BIT(15)
+#define INT_MASK		GENMASK(15, 0)
 #define RX_PKT_LEN		GENMASK(31, 16)
 
 #define MTK_REG_CSICR		0xc0
@@ -565,6 +566,7 @@ static void btmtksdio_txrx_work(struct work_struct *work)
 		 * FIFO.
 		 */
 		sdio_writel(bdev->func, int_status, MTK_REG_CHISR, NULL);
+		int_status &= INT_MASK;
 
 		if ((int_status & FW_MAILBOX_INT) &&
 		    bdev->data->chipid == 0x7921) {
-- 
2.25.1