Messages in this thread |  | | | Date | Fri, 26 Feb 2010 11:52:07 -0500 (EST) | | From | Alan Stern <> | | Subject | Re: USB mass storage and ARM cache coherency |
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On Fri, 26 Feb 2010, Catalin Marinas wrote:
> For mmap'ed pages (and present in the page cache), is it guaranteed that > the HCD driver won't write to it once it has been mapped into user > space? If that's the case, it may solve the problem by just reversing > the meaning of PG_arch_1 on ARM and assume that a newly allocated page > has dirty D-cache by default.
Nothing is guaranteed. The HCD will write to wherever it is asked. If a driver does input to an mmap'ed page, the HCD won't even know that the page is mmap'ed.
Alan Stern
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