diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c
index 00d5219094e5..8fddd26288e8 100644
--- a/drivers/mailbox/mtk-cmdq-mailbox.c
+++ b/drivers/mailbox/mtk-cmdq-mailbox.c
@@ -18,7 +18,6 @@
 #include <linux/of_device.h>
 
 #define CMDQ_OP_CODE_MASK		(0xff << CMDQ_OP_CODE_SHIFT)
-#define CMDQ_IRQ_MASK			0xffff
 #define CMDQ_NUM_CMD(t)			(t->cmd_buf_size / CMDQ_INST_SIZE)
 
 #define CMDQ_CURR_IRQ_STATUS		0x10
@@ -72,6 +71,7 @@ struct cmdq {
 	void __iomem		*base;
 	u32			irq;
 	u32			thread_nr;
+	u32			irq_mask;
 	struct cmdq_thread	*thread;
 	struct clk		*clock;
 	bool			suspended;
@@ -285,11 +285,11 @@ static irqreturn_t cmdq_irq_handler(int irq, void *dev)
 	unsigned long irq_status, flags = 0L;
 	int bit;
 
-	irq_status = readl(cmdq->base + CMDQ_CURR_IRQ_STATUS) & CMDQ_IRQ_MASK;
-	if (!(irq_status ^ CMDQ_IRQ_MASK))
+	irq_status = readl(cmdq->base + CMDQ_CURR_IRQ_STATUS) & cmdq->irq_mask;
+	if (!(irq_status ^ cmdq->irq_mask))
 		return IRQ_NONE;
 
-	for_each_clear_bit(bit, &irq_status, fls(CMDQ_IRQ_MASK)) {
+	for_each_clear_bit(bit, &irq_status, cmdq->thread_nr) {
 		struct cmdq_thread *thread = &cmdq->thread[bit];
 
 		spin_lock_irqsave(&thread->chan->lock, flags);
@@ -473,6 +473,9 @@ static int cmdq_probe(struct platform_device *pdev)
 		dev_err(dev, "failed to get irq\n");
 		return -EINVAL;
 	}
+
+	cmdq->thread_nr = (u32)(unsigned long)of_device_get_match_data(dev);
+	cmdq->irq_mask = GENMASK(cmdq->thread_nr - 1, 0);
 	err = devm_request_irq(dev, cmdq->irq, cmdq_irq_handler, IRQF_SHARED,
 			       "mtk_cmdq", cmdq);
 	if (err < 0) {
@@ -489,7 +492,6 @@ static int cmdq_probe(struct platform_device *pdev)
 		return PTR_ERR(cmdq->clock);
 	}
 
-	cmdq->thread_nr = (u32)(unsigned long)of_device_get_match_data(dev);
 	cmdq->mbox.dev = dev;
 	cmdq->mbox.chans = devm_kcalloc(dev, cmdq->thread_nr,
 					sizeof(*cmdq->mbox.chans), GFP_KERNEL);