Bug 31154

Summary:

EIZO S2242W has invalid extension block, no display

Product:

DRI

Reporter:

sam tygier <samtygier>

Component:

DRM/Radeon

Assignee:

Default DRI bug account <dri-devel>

Status:

RESOLVED FIXED

QA Contact:

Severity:

normal

Priority:

medium

Version:

unspecified

Hardware:

Other

OS:

Linux (All)

Whiteboard:

i915 platform:

i915 features:

Attachments:

Description	Flags
0001-DRM-ignore-invalid-EDID-extensions.patch	none

Description sam tygier 2010-10-27 01:33:47 UTC

i have a EIZO S2242W display, and radeon HD3650

with 2.6.34 it worked fine. only the base block of the EDID was read:
	EDID:
		00ffffffffffff0015c3042001010101
		1113010380301e78eaf5c5a85337ae25
		125054a10800a94081808140b3000101
		010101010101283c80a070b023403020
		3600da291100001a000000ff00323530
		32363034390a20202020000000fd003b
		3d1f4c11000a202020202020000000fc
		005332323432570a2020202020200154

since 2.6.35 (i noticed at rc4) it will not display to the monitor past very early boot messages. X wont display, neither will VTs. this is because drm_edid.c now reads extension blocks, and the EZIO gives a block of zeros for the extension block.

kernel: [    6.371608] [drm:drm_edid_block_valid] *ERROR* Raw EDID:
kernel: [    6.371644] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
kernel: [    6.371646] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
kernel: [    6.371648] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
kernel: [    6.371650] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
kernel: [    6.371652] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
kernel: [    6.371654] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
kernel: [    6.371656] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
kernel: [    6.371658] <3>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
kernel: [    6.371660] 
kernel: [    6.371664] radeon 0000:08:00.0: DVI-I-1: EDID block 1 invalid.

booting with radeon.modeset=0 seems to by pass this so that i have a working system.

i have bisected the change to:
61e57a8d72f2336faf39b5d940215cf085e01e6e is the first bad commit
commit 61e57a8d72f2336faf39b5d940215cf085e01e6e
Author: Adam Jackson <ajax <at> redhat.com>
Date:   Mon Mar 29 21:43:18 2010 +0000
 drm/edid: Fix secondary block fetch.

Comment 1 sam tygier 2010-10-27 01:39:12 UTC

there is some discussion at http://thread.gmane.org/gmane.comp.video.dri.devel/50127

Comment 2 sam tygier 2010-10-27 01:40:35 UTC

Created attachment 39803 [details] [review]
0001-DRM-ignore-invalid-EDID-extensions.patch

this patch skips over invalid extension blocks, allowing the valid base block to be returned, and my monitor to work.

Comment 3 sam tygier 2010-10-28 15:36:56 UTC

tested with fresh torvalds/linux-2.6.git kernel, 81280572ca6f54009edfa4deee563e8678784218

the issue is still present, and the patch still applies cleanly and fixes it.

Comment 4 sam tygier 2010-11-03 04:37:52 UTC

https://bugs.launchpad.net/linux/+bug/601376/comments/44 seems to be the same issue on nvidia card, with a different monitor

Comment 5 sam tygier 2010-11-13 11:10:12 UTC

i confirmed that this is fixed in linus' tree by the recent dri merge.

commit is 0ea75e23356f73b4300492e04a62c90787a55c2d

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