media: atomisp: improve error handling in gc2235_detect()

Static analysis reports this representative problem

atomisp-gc2235.c:867:20: warning: The right operand
  of '|' is a garbage value
        id = ((high << 8) | low);
                          ^ ~~~
When gc2235_read_reg() fails, its return val is never written.

For gc2235_detect(), high and low are or-ed and compared
with GC2235_ID, 0x2235.  Initialize both to 0 and skip
checking the read returns, it's errors are not passed up, only
-ENODEV is.

Link: https://lore.kernel.org/linux-media/20210521194805.2078135-1-trix@redhat.com
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/staging/media/atomisp/i2c/atomisp-gc2235.c b/drivers/staging/media/atomisp/i2c/atomisp-gc2235.c
index 9363c1a52ae9b3ee231fcb077676c930b4292e43..4d769590f2d3245d07f7cb2e0071baabef5cd3e6 100644 (file)
--- a/drivers/staging/media/atomisp/i2c/atomisp-gc2235.c
+++ b/drivers/staging/media/atomisp/i2c/atomisp-gc2235.c
@@ -849,21 +849,14 @@ static int gc2235_get_fmt(struct v4l2_subdev *sd,
 static int gc2235_detect(struct i2c_client *client)
 {
        struct i2c_adapter *adapter = client->adapter;
-       u16 high, low;
-       int ret;
+       u16 high = 0, low = 0;
        u16 id;
 
        if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
                return -ENODEV;
 
-       ret = gc2235_read_reg(client, GC2235_8BIT,
-                             GC2235_SENSOR_ID_H, &high);
-       if (ret) {
-               dev_err(&client->dev, "sensor_id_high = 0x%x\n", high);
-               return -ENODEV;
-       }
-       ret = gc2235_read_reg(client, GC2235_8BIT,
-                             GC2235_SENSOR_ID_L, &low);
+       gc2235_read_reg(client, GC2235_8BIT, GC2235_SENSOR_ID_H, &high);
+       gc2235_read_reg(client, GC2235_8BIT, GC2235_SENSOR_ID_L, &low);
        id = ((high << 8) | low);
 
        if (id != GC2235_ID) {