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    |   xen-devel
Re: [Xen-devel] Fbdev graphics broken in xen/next dom0 
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On 03/12/2010 04:44 PM, Eamon Walsh wrote:
 
I have narrowed the problem down: it has something to do with mmap of
/dev/fb0 not syncing.  The attached C code mmaps /dev/fb0 and writes
some random bits.  On a configuration that does work (2.6.31.4 on
4.0-rc6, or xen/next on bare metal) the random bits are visible on the
screen.  With xen/next on 4.0-rc6, nothing is visible.  Calling msync()
before the sleep has no effect.  Also, using write() on /dev/fb0 always
works so it appears to be mmap related.
 
Yes.  I suspect there's a missing VM_IO in there, and so the mmap is 
mapping the wrong pages (if you're lucky you might be able to crash the 
machine to see something juicy). 
    J
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