target/linux/bcm27xx/patches-5.10/950-0225-media-ov5647-Fix-return-codes-from-ov5647_write-ov56.patch

   1 From 0a17f217911f989cd58df868f902b488088a1398 Mon Sep 17 00:00:00 2001
   2 From: David Plowman <david.plowman@raspberrypi.org>
   3 Date: Wed, 15 Jan 2020 13:40:38 +0000
   4 Subject: [PATCH] media: ov5647: Fix return codes from
   5  ov5647_write/ov5647_read functions.
   6
   7 Previously they were returning positive non-zero codes for success,
   8 which were getting passed up the call stack. Since release 4.19,
   9 do_dentry_open (fs/open.c) has been catching these and flagging an
  10 error. (So this driver has been broken since that date.)
  11
  12 Fixes: 3c2472a [media] media: i2c: Add support for OV5647 sensor
  13 Signed-off-by: David Plowman <david.plowman@raspberrypi.org>
  14 Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
  15 ---
  16  drivers/media/i2c/ov5647.c | 30 +++++++++++++++++++++++++++---
  17  1 file changed, 27 insertions(+), 3 deletions(-)
  18
  19 --- a/drivers/media/i2c/ov5647.c
  20 +++ b/drivers/media/i2c/ov5647.c
  21 @@ -214,9 +214,18 @@ static int ov5647_write(struct v4l2_subd
  22         struct i2c_client *client = v4l2_get_subdevdata(sd);
  23
  24         ret = i2c_master_send(client, data, 3);
  25 -       if (ret < 0)
  26 +       /*
  27 +        * Writing the wrong number of bytes also needs to be flagged as an
  28 +        * error. Success needs to produce a 0 return code.
  29 +        */
  30 +       if (ret == 3) {
  31 +               ret = 0;
  32 +       } else {
  33                 dev_dbg(&client->dev, "%s: i2c write error, reg: %x\n",
  34                                 __func__, reg);
  35 +               if (ret >= 0)
  36 +                       ret = -EINVAL;
  37 +       }
  38
  39         return ret;
  40  }
  41 @@ -228,16 +237,31 @@ static int ov5647_read(struct v4l2_subde
  42         struct i2c_client *client = v4l2_get_subdevdata(sd);
  43
  44         ret = i2c_master_send(client, data_w, 2);
  45 -       if (ret < 0) {
  46 +       /*
  47 +        * A negative return code, or sending the wrong number of bytes, both
  48 +        * count as an error.
  49 +        */
  50 +       if (ret != 2) {
  51                 dev_dbg(&client->dev, "%s: i2c write error, reg: %x\n",
  52                         __func__, reg);
  53 +               if (ret >= 0)
  54 +                       ret = -EINVAL;
  55                 return ret;
  56         }
  57
  58         ret = i2c_master_recv(client, val, 1);
  59 -       if (ret < 0)
  60 +       /*
  61 +        * The only return value indicating success is 1. Anything else, even
  62 +        * a non-negative value, indicates something went wrong.
  63 +        */
  64 +       if (ret == 1) {
  65 +               ret = 0;
  66 +       } else {
  67                 dev_dbg(&client->dev, "%s: i2c read error, reg: %x\n",
  68                                 __func__, reg);
  69 +               if (ret >= 0)
  70 +                       ret = -EINVAL;
  71 +       }
  72
  73         return ret;
  74  }