[EXT] Re: [PATCH] rtc: pcf2127: fix uninitialized variable msg

[Priyanka Jain (OSS)]

>-----Original Message-----
>From: U-Boot <u-boot-bounces at lists.denx.de> On Behalf Of Biwen Li (OSS)
>Sent: Friday, July 10, 2020 7:24 AM
>To: Rasmus Villemoes <rasmus.villemoes at prevas.dk>; Biwen Li (OSS)
><biwen.li at oss.nxp.com>; Jagdish Gediya <jagdish.gediya at nxp.com>; Priyanka
>Jain <priyanka.jain at nxp.com>
>Cc: Jiafei Pan <jiafei.pan at nxp.com>; u-boot at lists.denx.de
>Subject: RE: [EXT] Re: [PATCH] rtc: pcf2127: fix uninitialized variable msg
>
>>
>> On 09/07/2020 13.38, Biwen Li wrote:
>> >>
>> >> On 09/07/2020 12.58, Biwen Li wrote:
>> >>> From: Biwen Li <biwen.li at nxp.com>
>> >>>
>> >>> Fix uninitialized variable msg
>> >>>
>> >>>       struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
>> >>> -     struct i2c_msg msg;
>> >>> +     struct i2c_msg msg = {0};
>> >>>       int ret;
>> >>>
>> >>>       /* Set the address of the start register to be read */
>> >>>
>> >>
>> >> I assume it's the
>> >>
>> >>         msg.flags |= I2C_M_RD;
>> >>
>> >> line that is warned about (please include such info)? Isn't the
>> >> right fix to replace that by
>> >>
>> >>         msg.flags = I2C_M_RD;
>> >>
>> >> ?
>> > Two lines("struct i2c msg;" and "msg.flags |= I2C_M_RD") are warned
>> > by
>> build system.
>>
>> What? That doesn't make sense. Perhaps your compiler is just friendly
>> enough to show you the declaration of the struct i2c_msg, but clearly
>> declaring an automatic variable without initializing it is not, by
>> itself, wrong. Otherwise "int ret;" in that very same function should
>> be warned about, and 100000 other instances in any code base written in C.
>>
>> Please show the exact output from the compiler and the compiler version.
>Sorry, acctually not build system. It's code analysis tool.

Can you please update subject or description stating that you are fixing issue reported by static analysis tool coverity

Thanks
Priyanka

>Such as:
>Declaring variable msg without initializer. (struce i2c_msg msg;) Uninitialized
>scalar variable (UNINIT),  uninit_use: Using uninitialized value
>msg.flags.(msg.flags |= I2C_M_RD)
>>
>> > Initializing msg variable will be better.
>>
>> No, understanding the cause of the warning and fixing that is clearly better.
>>
>> Rasmus