[U-Boot] [PATCH v4 2/2] hwmon: do not init sensors on startup

Wolfgang Denk wd at denx.de
Mon Aug 1 15:28:32 CEST 2011


Dear Heiko Schocher,

In message <1312196898-20228-1-git-send-email-hs at denx.de> you wrote:
> The U-Boot Design Principles[1] clearly say:
> 
>   Initialize devices only when they are needed within U-Boot, i.e. don't
>   initialize the Ethernet interface(s) unless U-Boot performs a download
>   over Ethernet; don't initialize any IDE or USB devices unless U-Boot
>   actually tries to load files from these, etc. (and don't forget to
>   shut down these devices after using them - otherwise nasty things may
>   happen when you try to boot your OS).
> 
> So, do not initialize and read the sensors on startup.
...
> - changes since v3
>   do not initialize static sensor_initialized with 0
...
> +static unsigned long sensor_initialized = 0xffffffff;

Ummm.... no.  You failed to understand what the checkpatch error
means.

There is no need to explicitly static variables with 0, because this
is their default value if you leave them unitialized - unintialized
data is allocated in the BSS segment, and thus get automatically
initialized as 0.

The code above enforces allocation ion the data segment, i. e. it
increses the (flash) memory footprint.

Please undo this.  Just omit the "= 0" par tin the declaration all
together.

Thanks.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
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