[U-Boot] [PATCH 1/6] usb: ehci: mx6: Add support for i.MX6SL

[Igor Grinberg]

Hi Nikolay,

On 06/16/14 17:33, Nikolay Dimitrov wrote:
> Hi Igor,
> 
> My personal opinion is that unless you intend to run the binary on multiple IMX6 variants,

That is exactly what we do already (code is on the way) and IMO what
we should aim for.

> there's no
> need to do expensive checks in runtime, when you can do the same at compile-time.

Why do you think it is expensive? Any benchmarks?
Also, the solution is what Marek already said, in short:
do the check once and store the result for future use...

> For me it's the
> same as choosing puts() vs printf() - you know at compile time whether you need to print arguments
> or not, so same with the USB controller base address - you know in advance that you target a specific
> CPU variant and not the other ones.

For me it is just an artificial complication which prevents single binary for
i.MX6 based boards.
Don't get me wrong, I think that in your board code you can choose which
approach you want, whether it will be single or multi binary, but this
is i.MX6 (and possibly future i.MX*) USB code which can be used on many
i.MX6 boards.

> 
> To a certain extent I agree that it would be awesome to have the same code running on all IMX6
> variants, but the run-time checks will increase somewhat the binary footprint and U-Boot community has
> already gone to great efforts to remove unnecessary bloat.

Again, what are we talking about? A couple of bytes?

> My personal assumption is that such generic
> approach would be more tolerated in the Linux kernel.

For Linux kernel this is the only acceptable way now.


-- 
Regards,
Igor.