Messages in this thread | | | Date | Wed, 5 Nov 2008 12:55:49 -0500 | From | "Mike Frysinger" <> | Subject | Re: [PATCH] UIO: only call pgprot_noncached if defined |
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On Wed, Nov 5, 2008 at 12:42, Greg KH wrote: > On Wed, Nov 05, 2008 at 12:33:37PM -0500, Mike Frysinger wrote: >> On Wed, Nov 5, 2008 at 11:33, Greg KH wrote: >> > On Wed, Nov 05, 2008 at 12:36:11PM +0100, Hans J. Koch wrote: >> >> There seem to be archs that cannot easily implement a sensible >> >> pgprot_noncached() function, so we should merge this patch. UIO doesn't >> >> compile on these archs right now. >> > >> > No, we should fix those arches to have that function at least NULLed >> > out. Isn't there only one, Blackfin? Putting #ifdefs in .c files is >> > not something we really want to do if at all possible. >> >> that was my question. this function isnt documented. if the hardware >> doesnt support it, is the right thing really for the arch to lie to >> drivers and not actually give back cached settings even though it >> asked for non-cached ? > > Probably not, it sounds like the arch needs to be fixed :)
i'd agree, but we're dealing with reality here: we're talking no-mmu and we can not do caching on a per-page basis while maintaining anything resembling usable performance. -mike
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