Merge tag 'backlight-next-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight

Pull backlight updates from Lee Jones:

   - handle 32bit overflow in pwm_bl

   - remove redundant code/checks in tps65217_bl and ili922x

* tag 'backlight-next-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight:
  backlight: ili922x: Remove redundant variable len
  backlight: tps65217_bl: Remove unnecessary default brightness check
  backlight: pwm_bl: Fix overflow condition

3 files changed, 7 insertions, 6 deletions

diff --git a/drivers/video/backlight/ili922x.c b/drivers/video/backlight/ili922x.c
index a9e9cef20ed6..2b6c6aaf4e14 100644
--- a/drivers/video/backlight/ili922x.c
+++ b/drivers/video/backlight/ili922x.c
@@ -251,7 +251,7 @@ static int ili922x_write(struct spi_device *spi, u8 reg, u16 value)
 	struct spi_transfer xfer_regindex, xfer_regvalue;
 	unsigned char tbuf[CMD_BUFSIZE];
 	unsigned char rbuf[CMD_BUFSIZE];
-	int ret, len = 0;
+	int ret;
 
 	memset(&xfer_regindex, 0, sizeof(struct spi_transfer));
 	memset(&xfer_regvalue, 0, sizeof(struct spi_transfer));
@@ -273,7 +273,6 @@ static int ili922x_write(struct spi_device *spi, u8 reg, u16 value)
 	ret = spi_sync(spi, &msg);
 
 	spi_message_init(&msg);
-	len = 0;
 	tbuf[0] = set_tx_byte(START_BYTE(ili922x_id, START_RS_REG,
 					 START_RW_WRITE));
 	tbuf[1] = set_tx_byte((value & 0xFF00) >> 8);
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 9bd17682655a..1c2289ddd555 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -79,14 +79,17 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb)
 static int compute_duty_cycle(struct pwm_bl_data *pb, int brightness)
 {
 	unsigned int lth = pb->lth_brightness;
-	int duty_cycle;
+	u64 duty_cycle;
 
 	if (pb->levels)
 		duty_cycle = pb->levels[brightness];
 	else
 		duty_cycle = brightness;
 
-	return (duty_cycle * (pb->period - lth) / pb->scale) + lth;
+	duty_cycle *= pb->period - lth;
+	do_div(duty_cycle, pb->scale);
+
+	return duty_cycle + lth;
 }
 
 static int pwm_backlight_update_status(struct backlight_device *bl)
diff --git a/drivers/video/backlight/tps65217_bl.c b/drivers/video/backlight/tps65217_bl.c
index 5ce8791f4523..380917c86276 100644
--- a/drivers/video/backlight/tps65217_bl.c
+++ b/drivers/video/backlight/tps65217_bl.c
@@ -239,8 +239,7 @@ tps65217_bl_parse_dt(struct platform_device *pdev)
 	}
 
 	if (!of_property_read_u32(node, "default-brightness", &val)) {
-		if (val < 0 ||
-			val > 100) {
+		if (val > 100) {
 			dev_err(&pdev->dev,
 				"invalid 'default-brightness' value in the device tree\n");
 			err = ERR_PTR(-EINVAL);