[U-Boot] [PATCH 0/4 V2] Add basic NVIDIA Tegra2 SoC support

[Wolfgang Denk]

Dear Tom Warren,

In message <AANLkTikCQ_0cNFRj_5S2zShcJ-2qyvi24yeH0DcqEPf_ at mail.gmail.com> you wrote:
>
> So instead of, say uart->lcr = 0, you'd prefer writel(0, uart->lcr),
> where writel = __arch_putl(v, a) = (*(volatile unsigned int *)(a) =
> (v))?

Please see the thread "ARM: Avoid compiler optimization for usages of
readb, writeb and friends."

> Is that different enough from 'uart->lcr = 0' to warrant the change?

Yes, it is - in recent (i. e. fixed) code.

> Does it add some HW barriers or forced read-before-write that the
> 'volatile' struct doesn't?

Yes, it does. See above.


Best regards,

Wolfgang Denk

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