[PATCH v4 04/14] media: ov772x: add checks for register read errors

[Akinobu Mita]

This change adds checks for register read errors and returns correct
error code.

Cc: Jacopo Mondi <jacopo+rene...@jmondi.org>
Cc: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
Cc: Hans Verkuil <hans.verk...@cisco.com>
Cc: Sakari Ailus <sakari.ai...@linux.intel.com>
Cc: Mauro Carvalho Chehab <mche...@s-opensource.com>
Reviewed-by: Jacopo Mondi <jac...@jmondi.org>
Signed-off-by: Akinobu Mita <akinobu.m...@gmail.com>
---
* v4
- No changes

 drivers/media/i2c/ov772x.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/media/i2c/ov772x.c b/drivers/media/i2c/ov772x.c
index b6223bf..3fdbe64 100644
--- a/drivers/media/i2c/ov772x.c
+++ b/drivers/media/i2c/ov772x.c
@@ -1146,7 +1146,7 @@ static int ov772x_set_fmt(struct v4l2_subdev *sd,
 static int ov772x_video_probe(struct ov772x_priv *priv)
 {
        struct i2c_client  *client = v4l2_get_subdevdata(&priv->subdev);
-       u8                  pid, ver;
+       int                 pid, ver, midh, midl;
        const char         *devname;
        int                 ret;
 
@@ -1156,7 +1156,11 @@ static int ov772x_video_probe(struct ov772x_priv *priv)
 
        /* Check and show product ID and manufacturer ID. */
        pid = ov772x_read(client, PID);
+       if (pid < 0)
+               return pid;
        ver = ov772x_read(client, VER);
+       if (ver < 0)
+               return ver;
 
        switch (VERSION(pid, ver)) {
        case OV7720:
@@ -1172,13 +1176,17 @@ static int ov772x_video_probe(struct ov772x_priv *priv)
                goto done;
        }
 
+       midh = ov772x_read(client, MIDH);
+       if (midh < 0)
+               return midh;
+       midl = ov772x_read(client, MIDL);
+       if (midl < 0)
+               return midl;
+
        dev_info(&client->dev,
                 "%s Product ID %0x:%0x Manufacturer ID %x:%x\n",
-                devname,
-                pid,
-                ver,
-                ov772x_read(client, MIDH),
-                ov772x_read(client, MIDL));
+                devname, pid, ver, midh, midl);
+
        ret = v4l2_ctrl_handler_setup(&priv->hdl);
 
 done:
-- 
2.7.4