Re: [Linux-fbdev-devel] Re: [PATCH] fbdev: Fix IO access in rivafb

From: Linus Torvalds
Date: Mon Nov 08 2004 - 14:36:21 EST




On Mon, 8 Nov 2004, Antonino A. Daplas wrote:
>
> How about this patch? This is almost the original macro in riva_hw.h,
> with the __force annotation.

Why not just use __raw_readl/__raw_writel?

That's what they exist for, and they still do any IO accesses correctly,
which a direct store does not do (it would seriously break on older
alphas, for example).

Of course, clearly the thing has never worked on things like alphas
anyway, but the point is that accessing IO memory with direct loads and
stores really _is_ fundamentally wrong, even if it happens to work on many
architectures. The keyword is "happens".

Linus
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