target/linux/bcm27xx/patches-5.15/950-0369-media-ov5647-Fix-return-codes-from-ov5647_write-ov56.patch

   1 From 4095981bf8a912e5e8f5d86ff305d974d506b091 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 | 38 ++++++++++++++++++++++++++++++++------
  17  1 file changed, 32 insertions(+), 6 deletions(-)
  18
  19 --- a/drivers/media/i2c/ov5647.c
  20 +++ b/drivers/media/i2c/ov5647.c
  21 @@ -587,7 +587,13 @@ static int ov5647_write16(struct v4l2_su
  22         int ret;
  23
  24         ret = i2c_master_send(client, data, 4);
  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 == 4) {
  31 +               ret = 0;
  32 +       } else {
  33                 dev_dbg(&client->dev, "%s: i2c write error, reg: %x\n",
  34                         __func__, reg);
  35                 return ret;
  36 @@ -603,10 +609,17 @@ static int ov5647_write(struct v4l2_subd
  37         int ret;
  38
  39         ret = i2c_master_send(client, data, 3);
  40 -       if (ret < 0) {
  41 +       /*
  42 +        * Writing the wrong number of bytes also needs to be flagged as an
  43 +        * error. Success needs to produce a 0 return code.
  44 +        */
  45 +       if (ret == 3) {
  46 +               ret = 0;
  47 +       } else {
  48                 dev_dbg(&client->dev, "%s: i2c write error, reg: %x\n",
  49                                 __func__, reg);
  50 -               return ret;
  51 +               if (ret >= 0)
  52 +                       ret = -EINVAL;
  53         }
  54
  55         return 0;
  56 @@ -619,17 +632,30 @@ static int ov5647_read(struct v4l2_subde
  57         int ret;
  58
  59         ret = i2c_master_send(client, data_w, 2);
  60 -       if (ret < 0) {
  61 +       /*
  62 +        * A negative return code, or sending the wrong number of bytes, both
  63 +        * count as an error.
  64 +        */
  65 +       if (ret != 2) {
  66                 dev_dbg(&client->dev, "%s: i2c write error, reg: %x\n",
  67                         __func__, reg);
  68 +               if (ret >= 0)
  69 +                       ret = -EINVAL;
  70                 return ret;
  71         }
  72
  73         ret = i2c_master_recv(client, val, 1);
  74 -       if (ret < 0) {
  75 +       /*
  76 +        * The only return value indicating success is 1. Anything else, even
  77 +        * a non-negative value, indicates something went wrong.
  78 +        */
  79 +       if (ret == 1) {
  80 +               ret = 0;
  81 +       } else {
  82                 dev_dbg(&client->dev, "%s: i2c read error, reg: %x\n",
  83                                 __func__, reg);
  84 -               return ret;
  85 +               if (ret >= 0)
  86 +                       ret = -EINVAL;
  87         }
  88
  89         return 0;