Messages in this thread | | | Date | Fri, 10 Jul 2009 15:05:19 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: Intel BIOS - Corrupted low memory at ffff880000004200 |
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On Fri, 10 Jul 2009, Alexey Fisher wrote: > Ingo Molnar schrieb: > > * Matthew Garrett <mjg59@srcf.ucam.org> wrote: > > > > > On Mon, Jul 06, 2009 at 06:24:47PM +0200, Alexey Fisher wrote: > > > > Hallo Ingo, Richard. > > > > > > > > I'm getting "Corrupted low memory" trace with my Intel DG45ID board > > > > after resume. This board has different dmi-bios-vendor... so probably it > > > > will be nice to have it in your patch. > > > I'm beginning to think that we should be doing this on all hardware, > > > perhaps with a kernel option to disable it for embedded devices that > > > really need that 64K. The low-memory corruption issue seems to be very > > > widespread. > > > > The problem is that the BIOS corrupted memory that it also marked as > > 'usable' in its E820 map it gave to the kernel. If that memory is not > > usable, it should not have been marked as such. Also, some of the reports > > showed corruption beyond this range so the workaround is not universal. > > > > So i'd really like to know what is happening there, instead of just zapping > > support for 64K of RAM on the majority of Linux systems. > > > > We might end up doing the same thing in the end (i.e. disable that 64k of > > RAM) - but it should be an informed decision, not a wild stab in the dark. > > > > Ingo > > If i make memory dump like "dd if=/dev/mem of=memdump.dd bs=64k count=1" > before and after suspend. Will it help you find out whats happening.
The corrupted low memory printks contain the modifications. Can you post them please ?
Thanks,
tglx
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