[U-Boot] [PATCH] mx31: Improve the handling of unidentified silicon version

[Stefano Babic <sbabic@denx.de>]

On 06/14/2011 06:31 PM, Fabio Estevam wrote:
> MX31 Reference Manual states the following possible values for the silicon revision:
> 

Hi Fabio,

> However it is possible to find some pre-production silicon on some old hardware, such as MX31ADS
> that shows srev = 0x20.
> 
> The following message is the currently displayed on such MX31ADS board:
> 
> CPU:   Freescale i.MX31 rev 2.0 unknown at 531 MHz.Reset cause: WDOG
> 
> With this patch we see a better message like:
> 
> CPU:   Freescale i.MX31 rev 0.0 (unknown revision) at 531 MHz.Reset cause: WDOG

Why is the new output better as we have now ? You drop the output of
the srev register, and then we cannot get which strange silicon version
is running without patching the code.

>  		if (srev == mx31_cpu_type[i].srev)
>  			return mx31_cpu_type[i].v;
>  
> -	return srev | 0x8000;
> +	return 0x8000;

IMHO in the case the revision is not recognized, it is better to print
the value of the srev register, as it is done now. This can be a useful
information and printing a fixed "0.0" version does not say anything
about the processor.

Best regards,
Stefano Babic

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