Revision c1230df7e19e0f27655c0eb9d966c7e03be7cc50 authored by Paulo Zanoni on 03 May 2012, 01:55:43 UTC, committed by Daniel Vetter on 03 May 2012, 13:55:38 UTC
While testing with the intel_infoframes tool on gen4, I see that when
video DIP is disabled, what we write to the DATA memory is not exactly
what we read back later.

This regression has been introduce in

commit 64a8fc0145a1d0fdc25fc9367c2e6c621955fb3b
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date:   Thu Sep 22 11:16:00 2011 +0530

    drm/i915: fix ILK+ infoframe support

That commit was setting VIDEO_DIP_CTL to 0 when initializing, which
caused the problem.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=43947
Cc: stable@kernel.org
Tested-by: Yang Guang <guang.a.yang@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
[danvet: Pimped commit message by using the usual commit citation
layout.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
1 parent 6200497
Raw File
bad_memory.txt
March 2008
Jan-Simon Moeller, dl9pf@gmx.de


How to deal with bad memory e.g. reported by memtest86+ ?
#########################################################

There are three possibilities I know of:

1) Reinsert/swap the memory modules

2) Buy new modules (best!) or try to exchange the memory
   if you have spare-parts

3) Use BadRAM or memmap

This Howto is about number 3) .


BadRAM
######
BadRAM is the actively developed and available as kernel-patch
here:  http://rick.vanrein.org/linux/badram/

For more details see the BadRAM documentation.

memmap
######

memmap is already in the kernel and usable as kernel-parameter at
boot-time.  Its syntax is slightly strange and you may need to
calculate the values by yourself!

Syntax to exclude a memory area (see kernel-parameters.txt for details):
memmap=<size>$<address>

Example: memtest86+ reported here errors at address 0x18691458, 0x18698424 and
         some others. All had 0x1869xxxx in common, so I chose a pattern of
         0x18690000,0xffff0000.

With the numbers of the example above:
memmap=64K$0x18690000
 or
memmap=0x10000$0x18690000

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