[U-Boot] [PATCH 3/3] mpc5200: make i2c faster

[Wolfgang Denk]

Dear Jon,

In message <9e4733910903221959n452a067kd46b313b9b453ec3 at mail.gmail.com> you wrote:
>
> > You did not answer my question in which way this actually makes I2C
> > faster? Where do we save time, and how much?
> 
> I increased the retry loop to 10,000.  This definitely makes my system
> faster. On my bus the actual i2c delay is 40-55us.  The original code
> always delayed 1,000us so for me it a gain of 940us on each i2c
> operation.  This is visible during things like probe.

Hm... you don't really convince me. Being "visible" is nice,  but  is
it  a  reason to change the code? I mean, if you said something like:
"without that patch operation FOO takes  20  seconds,  and  with  the
patch  it  takes  less than 3 seconds", then everybody can understand
why this is a good thing to do.

And: the I2C probe operation itself is just a  debug  thing,  nothing
you  do in normal operation, so it doesn't look that time critical to
me.


I agree that the change itself looks harmless,  and  I'm  willing  to
accept  it,  but  at  least make sure not to reduce the total timeout
values - that would require re-testing on some boards.

Best regards,

Wolfgang Denk

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