On 10/6/20 5:41 AM, Sakari Ailus wrote:
> Hi Tom,
>
> On Fri, Aug 28, 2020 at 07:55:18AM -0700, trix@xxxxxxxxxx wrote:
>> From: Tom Rix <trix@xxxxxxxxxx>
>>
>> clang static analysis flags this representative problem
>>
>> drivers/media/i2c/ov7670.c:1463:9: warning: Assigned
>> value is garbage or undefined
>> *value = gain;
>> ^ ~~~~
>>
>> gain is set by a successful call to ov7670_read()
>>
>> So check that ov7670_read() is successful.
>>
>> The remaining static analysis problems are false positives.
>> There appears to be a limitation with checking the
>> aggregated returns.
>>
>> Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
>> ---
>> drivers/media/i2c/ov7670.c | 17 +++++++++++++----
>> 1 file changed, 13 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/media/i2c/ov7670.c b/drivers/media/i2c/ov7670.c
>> index b42b289faaef..001d4b09db72 100644
>> --- a/drivers/media/i2c/ov7670.c
>> +++ b/drivers/media/i2c/ov7670.c
>> @@ -929,6 +929,8 @@ static int ov7670_set_hw(struct v4l2_subdev *sd, int hstart, int hstop,
>> ret = ov7670_write(sd, REG_HSTART, (hstart >> 3) & 0xff);
>> ret += ov7670_write(sd, REG_HSTOP, (hstop >> 3) & 0xff);
>> ret += ov7670_read(sd, REG_HREF, &v);
>> + if (ret)
>> + return ret;
> Thanks for the patch.
>
> While the patch fixes a bug, could you also fix adding the return values?
> These are valid error codes to begin with, but it makes no sense to add
> them together.
Yes. That is a problem, a general problem with this file.
I count 10+
I'll see if fixing the general problem also fixes this problem.
Tom
>
>> v = (v & 0xc0) | ((hstop & 0x7) << 3) | (hstart & 0x7);
>> msleep(10);
>> ret += ov7670_write(sd, REG_HREF, v);
>> @@ -938,6 +940,8 @@ static int ov7670_set_hw(struct v4l2_subdev *sd, int hstart, int hstop,
>> ret += ov7670_write(sd, REG_VSTART, (vstart >> 2) & 0xff);
>> ret += ov7670_write(sd, REG_VSTOP, (vstop >> 2) & 0xff);
>> ret += ov7670_read(sd, REG_VREF, &v);
>> + if (ret)
>> + return ret;
>> v = (v & 0xf0) | ((vstop & 0x3) << 2) | (vstart & 0x3);
>> msleep(10);
>> ret += ov7670_write(sd, REG_VREF, v);
>> @@ -1460,6 +1464,8 @@ static int ov7670_g_gain(struct v4l2_subdev *sd, __s32 *value)
>> unsigned char gain;
>>
>> ret = ov7670_read(sd, REG_GAIN, &gain);
>> + if (ret)
>> + return ret;
>> *value = gain;
>> return ret;
>> }
>> @@ -1470,11 +1476,14 @@ static int ov7670_s_gain(struct v4l2_subdev *sd, int value)
>> unsigned char com8;
>>
>> ret = ov7670_write(sd, REG_GAIN, value & 0xff);
>> + if (ret)
>> + return ret;
>> /* Have to turn off AGC as well */
>> - if (ret == 0) {
>> - ret = ov7670_read(sd, REG_COM8, &com8);
>> - ret = ov7670_write(sd, REG_COM8, com8 & ~COM8_AGC);
>> - }
>> + ret = ov7670_read(sd, REG_COM8, &com8);
>> + if (ret)
>> + return ret;
>> + ret = ov7670_write(sd, REG_COM8, com8 & ~COM8_AGC);
>> +
>> return ret;
>> }
>>
