Bug 94197

Summary: SAD counting bug inintel/linux-4.0.4/drivers/gpu/drm/drm_edid.c
Product: DRI Reporter: Arturo Pérez <artur999555>
Component: DRM/IntelAssignee: Mengdong Lin <mengdong.lin>
Status: CLOSED FIXED QA Contact: Intel GFX Bugs mailing list <intel-gfx-bugs>
Severity: normal    
Priority: medium CC: intel-gfx-bugs
Version: unspecified   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: BSW/CHT i915 features:
Attachments:
Description Flags
EDID captured from Krell using OpenELEC/Kodi instructions
none
[PATCH] drm/edid: Extract SADs properly from multiple audio data blocks none

Description Arturo Pérez 2016-02-17 16:31:23 UTC 
Created attachment 121817 [details]
EDID captured from Krell using OpenELEC/Kodi instructions

I have a Krell Foundation non-4K which has a strange EDID.  It does not have one audio block with multiple SAD within it as do Marantz receivers but rather it has several audio blocks, one after another.

When I connect the Foundation to an Asrock Beebox running OpenELEC the ELD data structure ends up with only one element.

I think that is because of these lines of code starting at line 3157 in intel/linux-4.0.4/drivers/gpu/drm/drm_edid.c

 case AUDIO_BLOCK:
 /* Audio Data Block, contains SADs */
 sad_count = dbl / 3;
 if (dbl >= 1)
     memcpy(eld + 20 + mnl, &db[1], dbl);
 break;

For the Krell, the sad_count would need to be incremented instead of just set to the value from the EDID.  I do not know how this code would keep all the audio blocks in such a fashion.

Now, if you tell me that the Foundation is doing this incorrectly I am more than willing to report that to Krell. ;-)

Krill Foundation manual: http://krellonline.com/downloads/FoundationProcessorOwnersReference_web.pdf
Comment 1 Arturo Pérez 2016-02-17 16:41:13 UTC 
das-schoen:~ # uname -r
4.4.1
das-schoen:~ # uname -m
x86_64

Machine: Asrock Beebox n3000
OS: OpenELEC
OpenELEC (community) Version: devel-20160205163951-r22034-g76ba946
OpenELEC git: 76ba94657514eb7ed4c0b42546b7b9d9f7bb5ddb


Connected via HDMI.
Comment 2 Ville Syrjala 2016-03-01 20:04:57 UTC 
Created attachment 122065 [details] [review]
[PATCH] drm/edid: Extract SADs properly from multiple audio data  blocks

Glanced at the specs a bit, and ended up writing a patch while reading. Please test.
Comment 3 Arturo Pérez 2016-03-05 18:20:53 UTC 
Tested with the below build from OpenELEC group.  It correctly detects all the audio devices as show by the cat'ing the eld device.

das-schoen:/proc/asound/card0 # uname -r
4.3.0
das-schoen:/proc/asound/card0 # uname -m
x86_64

Linux version 4.3.0 (mattd@ubuntu1510-VirtualBox) (gcc version 4.9.3 (GCC) ) #1 SMP Wed Mar 2 10:50:09 CST 2016

In case you want to look at it
das-schoen:~ # dmesg | pastebinit
http://sprunge.us/YTiE

das-schoen:/proc/asound/card0 # cat eld\#2.0 | pastebinit
http://sprunge.us/RDQA
Comment 4 MattDevo 2016-03-05 21:52:07 UTC 
Comment on attachment 122065 [details] [review]
[PATCH] drm/edid: Extract SADs properly from multiple audio data  blocks

Review of attachment 122065 [details] [review]:
-----------------------------------------------------------------

fix confirmed by reporter using custom OpenELEC build with kernel 4.3 and patch applied
Comment 5 Chris Wilson 2016-03-30 16:48:41 UTC 
commit 7c01878254daadbb91f5b1137b7404d952e3931b
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date:   Wed Mar 9 22:07:46 2016 +0200

    drm/edid: Extract SADs properly from multiple audio data blocks

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