[PATCH 1/3] drm/ssd130x: fix column and row end address in partial updates for ssd132x

[Amit Barzilai]

On partial screen updates, SSD132X controllers expect to get the
rectangle addresses as arguments of the "Set Column Address" and "Set
Row Address" commands. Each command expects the start address and end
address of the row/column in absolute format, however the end
addresses were being sent in a relative format (relative to the start
address).

The relative end addresses work only when the start address is 0. In
those situations, there is no value difference between relative and
absolute addresses.

Fixes: fdd591e00a9c9 ("drm/ssd130x: Add support for the SSD132x OLED controller family")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Amit Barzilai <amit.barzilai22@xxxxxxxxx>
---
 drivers/gpu/drm/solomon/ssd130x.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c
index c77455b1834d..77aa5585a46c 100644
--- a/drivers/gpu/drm/solomon/ssd130x.c
+++ b/drivers/gpu/drm/solomon/ssd130x.c
@@ -864,12 +864,13 @@ static int ssd132x_update_rect(struct ssd130x_device *ssd130x,
 	 */
 
 	/* Set column start and end */
-	ret = ssd130x_write_cmd(ssd130x, 3, SSD132X_SET_COL_RANGE, x / segment_width, columns - 1);
+	ret = ssd130x_write_cmd(ssd130x, 3, SSD132X_SET_COL_RANGE, x / segment_width,
+				x / segment_width + columns - 1);
 	if (ret < 0)
 		return ret;
 
 	/* Set row start and end */
-	ret = ssd130x_write_cmd(ssd130x, 3, SSD132X_SET_ROW_RANGE, y, rows - 1);
+	ret = ssd130x_write_cmd(ssd130x, 3, SSD132X_SET_ROW_RANGE, y, y + rows - 1);
 	if (ret < 0)
 		return ret;
 
-- 
2.54.0