Re: [PATCH 2/2] ARM: imx: Add mx53 support to common msl functions.

["Eric Bénard" <eric@eukrea.com>]

Hi Dinh,

Le 04/11/2010 20:21, Nguyen Dinh-R00091 a écrit :
> Reading the ROM code is probably the most reliable way to get the correct
> silicon revision. Because the ROM that is on the chip is "most likely"
> up-to-date with the silicon. "Most likely" means that 95% of the time, when
> you get a new silicon, the ROM code will get updated. There is still a
> chance that a new silicon will not require a ROM update.
>
> Also the other reason is that sometimes the fuses that identify the silicon
> revision that are used by the IIM are sometimes not blown to reflect the
> correct revision in pre-production parts. MX51 is a post production part,
> so in theory, the fuses are blown correctly. But since we made MX51 boards
> available prior to going into production, reading from the IIM is not as
> reliable as reading the ROM.
>
Don't you think we should use the documented register which (if we believe the 
documentation) should be 100% reliable for production CPU instead of this 
undocumented method which from what you say is 95% reliable and here to handle 
the case of pre production CPU ?

The same problem occured on i.MX35 silicon 2.1 which where not correctly 
detected using the ROM code.

Eric