i2c: phytium: Fix potential divided by zero in i2c_phyt_master_regfile_isr()

opsiff · opsiff · commit 555716fb1c80 · 2026-05-27T09:58:34.000+08:00
deepin inclusion category: bugfix Fixes: 7db4ed0 ("i2c: phytium: Fixed the bug that processed unupdated data") Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
diff --git a/drivers/i2c/busses/phytium_i2c_v2/i2c-phyt-master.c b/drivers/i2c/busses/phytium_i2c_v2/i2c-phyt-master.c
@@ -462,13 +462,14 @@ static irqreturn_t i2c_phyt_master_regfile_isr(int this_irq, void *dev_id)
 		return IRQ_NONE;
 	}
 
-	head = i2c_phyt_read_reg(dev, FT_I2C_REGFILE_TX_HEAD) % dev->mng.tx_ring_cnt;
+	head = i2c_phyt_read_reg(dev, FT_I2C_REGFILE_TX_HEAD);
 	i2c_phyt_common_regfile_clear_rv2ap_int(dev, stat);
 	if (!dev->mng.tx_ring_cnt) {
 		dev_err(dev->dev, "tx_ring_cnt is zero\n");
 		spin_unlock(&dev->i2c_lock);
 		return IRQ_NONE;
 	}
+	head = head % dev->mng.tx_ring_cnt;
 
 	tail = dev->mng.cur_cmd_cnt % dev->mng.tx_ring_cnt;
 	do {

Original file line number	Diff line number	Diff line change
`@@ -462,13 +462,14 @@ static irqreturn_t i2c_phyt_master_regfile_isr(int this_irq, void *dev_id)`
`462`	`462`	`return IRQ_NONE;`
`463`	`463`	`}`
`464`	`464`
`465`		`- head = i2c_phyt_read_reg(dev, FT_I2C_REGFILE_TX_HEAD) % dev->mng.tx_ring_cnt;`
	`465`	`+ head = i2c_phyt_read_reg(dev, FT_I2C_REGFILE_TX_HEAD);`
`466`	`466`	`i2c_phyt_common_regfile_clear_rv2ap_int(dev, stat);`
`467`	`467`	`if (!dev->mng.tx_ring_cnt) {`
`468`	`468`	`dev_err(dev->dev, "tx_ring_cnt is zero\n");`
`469`	`469`	`spin_unlock(&dev->i2c_lock);`
`470`	`470`	`return IRQ_NONE;`
`471`	`471`	`}`
	`472`	`+ head = head % dev->mng.tx_ring_cnt;`
`472`	`473`
`473`	`474`	`tail = dev->mng.cur_cmd_cnt % dev->mng.tx_ring_cnt;`
`474`	`475`	`do {`