Re: ioremap_nocache problem?

Timur Tabi (ttabi@interactivesi.com)
Thu, 25 Jan 2001 09:56:32 -0600

** Reply to message from "Stephen C. Tweedie" <sct@redhat.com> on Thu, 25 Jan
2001 15:16:55 +0000

> ioremap*() is only supposed to be used on IO regions or reserved
> pages. If you haven't marked the pages as reserved, then iounmap will
> do the wrong thing, so it's up to you to reserve the pages.

Au contraire!

I mark the page as reserved when I ioremap() it. However, if I leave it marked
reserved, then iounmap() will not unmap it. If I mark it "unreserved" (i.e.
reset the reserved bit), then iounmap will unmap it, but it will decrement the
page counter to -1 and the whole system will crash soon thereafter.

I've been asking about this problem for months, but no one has bothered to help
me out.

-- 
Timur Tabi - ttabi@interactivesi.com
Interactive Silicon - http://www.interactivesi.com


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