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From 23f717168dc55f69ad517d3ab5f412d04a5afc0e Mon Sep 17 00:00:00 2001
From: David Plowman <david.plowman@raspberrypi.org>
Date: Wed, 15 Jan 2020 13:40:38 +0000
Subject: [PATCH] media: ov5647: Fix return codes from
ov5647_write/ov5647_read functions.
Previously they were returning positive non-zero codes for success,
which were getting passed up the call stack. Since release 4.19,
do_dentry_open (fs/open.c) has been catching these and flagging an
error. (So this driver has been broken since that date.)
Fixes: 3c2472a [media] media: i2c: Add support for OV5647 sensor
Signed-off-by: David Plowman <david.plowman@raspberrypi.org>
Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
---
drivers/media/i2c/ov5647.c | 30 +++++++++++++++++++++++++++---
1 file changed, 27 insertions(+), 3 deletions(-)
--- a/drivers/media/i2c/ov5647.c
+++ b/drivers/media/i2c/ov5647.c
@@ -214,9 +214,18 @@ static int ov5647_write(struct v4l2_subd
struct i2c_client *client = v4l2_get_subdevdata(sd);
ret = i2c_master_send(client, data, 3);
- if (ret < 0)
+ /*
+ * Writing the wrong number of bytes also needs to be flagged as an
+ * error. Success needs to produce a 0 return code.
+ */
+ if (ret == 3) {
+ ret = 0;
+ } else {
dev_dbg(&client->dev, "%s: i2c write error, reg: %x\n",
__func__, reg);
+ if (ret >= 0)
+ ret = -EINVAL;
+ }
return ret;
}
@@ -228,16 +237,31 @@ static int ov5647_read(struct v4l2_subde
struct i2c_client *client = v4l2_get_subdevdata(sd);
ret = i2c_master_send(client, data_w, 2);
- if (ret < 0) {
+ /*
+ * A negative return code, or sending the wrong number of bytes, both
+ * count as an error.
+ */
+ if (ret != 2) {
dev_dbg(&client->dev, "%s: i2c write error, reg: %x\n",
__func__, reg);
+ if (ret >= 0)
+ ret = -EINVAL;
return ret;
}
ret = i2c_master_recv(client, val, 1);
- if (ret < 0)
+ /*
+ * The only return value indicating success is 1. Anything else, even
+ * a non-negative value, indicates something went wrong.
+ */
+ if (ret == 1) {
+ ret = 0;
+ } else {
dev_dbg(&client->dev, "%s: i2c read error, reg: %x\n",
__func__, reg);
+ if (ret >= 0)
+ ret = -EINVAL;
+ }
return ret;
}
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