From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 20 Oct 2017 03:28:45 +0300
Subject: drm/panel: rpi-touchscreen: propagate errors in
 rpi_touchscreen_i2c_read()
Git-commit: 85b4587f8e94143bafb8b6a4003a5187b9a8753d
Patch-mainline: v4.16-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

There is one caller which checks whether rpi_touchscreen_i2c_read()
returns negative error codes.  Currently it can't because negative
error codes are truncated to u8, but that's easy to fix if we change the
type to int.

Fixes: 2f733d6194bd ("drm/panel: Add support for the Raspberry Pi 7" Touchscreen.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20171020002845.kar2wg7gqxg7tzqi@mwanda
Reviewed-by: Eric Anholt <eric@anholt.net>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
+++ b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
@@ -221,7 +221,7 @@ static struct rpi_touchscreen *panel_to_
 	return container_of(panel, struct rpi_touchscreen, base);
 }
 
-static u8 rpi_touchscreen_i2c_read(struct rpi_touchscreen *ts, u8 reg)
+static int rpi_touchscreen_i2c_read(struct rpi_touchscreen *ts, u8 reg)
 {
 	return i2c_smbus_read_byte_data(ts->i2c, reg);
 }