Bug 38170 - LG TV shows no signal attached to radeon via HDMI (and is improperly detected)
Summary: LG TV shows no signal attached to radeon via HDMI (and is improperly detected)
Status: RESOLVED INVALID
Alias: None
Product: xorg
Classification: Unclassified
Component: Driver/Radeon (show other bugs)
Version: 7.6 (2010.12)
Hardware: x86-64 (AMD64) Linux (All)
: medium normal
Assignee: xf86-video-ati maintainers
QA Contact: Xorg Project Team
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2011-06-10 16:06 UTC by Thomas Martitz
Modified: 2018-06-12 19:09 UTC (History)
1 user (show)

See Also:
i915 platform:
i915 features:


Attachments
dmesg without radeon.audio=0 (78.02 KB, text/plain)
2011-06-10 16:56 UTC, Thomas Martitz
no flags Details
xorg log without radeon.audio=0 (39.49 KB, text/plain)
2011-06-10 16:57 UTC, Thomas Martitz
no flags Details
dmesg with radeon.audio=0 (77.14 KB, text/plain)
2011-06-10 16:58 UTC, Thomas Martitz
no flags Details
xorg log with radeon.audio=0 (40.74 KB, text/plain)
2011-06-10 16:59 UTC, Thomas Martitz
no flags Details
dmesg with discrete selected in bios and plugging HDMI cable a few times (90.74 KB, text/plain)
2011-06-13 08:18 UTC, Thomas Martitz
no flags Details
Xorg.0.log with discrete selected in bios and plugging HDMI cable a few times (40.93 KB, text/plain)
2011-06-13 08:18 UTC, Thomas Martitz
no flags Details

Description Thomas Martitz 2011-06-10 16:06:21 UTC
When I attach my TV (LG 26LE5500) via HDMI, it is detected as '7" Goldstar Company Inc.' device, but xrandr seems to list the correct resolutions.

Worse though is that the TV shows no signal, it even says "No Signal" on the screen. This of course means I cannot attach my TV.

I don't know if it matters, but I'm using GPU switching via vgaswitcheroo.

Steps to reproduce:
0. Switch to radeon discrete graphics and restart X.
1. Attach TV via HDMI
2. Configure resolution
3. See no signal on the TV

Actual Result:
No signal/black screen on TV

Expected Result:
Desktop viewable on TV

Build Date & Platform:
I tried various Linux distributions, most of them with xserver-xorg-video-radeon 6.14 and kernel 2.6.38, i.e. Ubuntu 10.10 and 11.04, Linux Mint 10 and 11, Linux Mint DE, Fedora 15. All showed the same result.

Prod me if you need more information or if I can help debugging. I'm an experienced programmer for that matter.
Comment 1 Alex Deucher 2011-06-10 16:12:19 UTC
Please attach your xorg log and dmesg output.  If you are using 2.6.38 or newer, boot with radeon.audio=0 on the kernel command line in grub.
Comment 2 Thomas Martitz 2011-06-10 16:56:44 UTC
Created attachment 47834 [details]
dmesg without radeon.audio=0
Comment 3 Thomas Martitz 2011-06-10 16:57:38 UTC
Created attachment 47835 [details]
xorg log without radeon.audio=0
Comment 4 Thomas Martitz 2011-06-10 16:58:15 UTC
Created attachment 47836 [details]
dmesg with radeon.audio=0
Comment 5 Thomas Martitz 2011-06-10 16:59:10 UTC
Created attachment 47837 [details]
xorg log with radeon.audio=0
Comment 6 Thomas Martitz 2011-06-10 16:59:48 UTC
First of all, with radeon.audio=0 the TV indeed shows the desktop. Great. But I obviously don't have sound output. I forgot to mention in my initial post that the TV works when attached to a nvidia graphics card via DVI (using nouveau). But that's not surprising anymore.

Anyway, I attached the logs you requested.
I don't know if the i915 OOPSes matter.

FWIW, the HDMI audio output is the main reason I want to attach the TV, because my sound system is connected to the TV and I want to listen to music with it. You mentioned 2.6.38 and newer. Do older kernels work better in that matter?

Thanks for your help and amazingly quick response.
Comment 7 KavithaReddy 2011-06-13 00:50:29 UTC
(In reply to comment #6)
> First of all, with radeon.audio=0 the TV indeed shows the desktop. Great. But I
> obviously don't have sound output. I forgot to mention in my initial post that
> the TV works when attached to a nvidia graphics card via DVI (using nouveau).
> But that's not surprising anymore.
> Anyway, I attached the logs you requested.
> I don't know if the i915 OOPSes matter.
> FWIW, the HDMI audio output is the main reason I want to attach the TV, because
> my sound system is connected to the TV and I want to listen to music with it.
> You mentioned 2.6.38 and newer. Do older kernels work better in that matter?
> Thanks for your help and amazingly quick response.


 Can you please try :

1) Disable onboard audio 
2) Un-mute sound device with 
   alsamixer -c <Card ID#>
Comment 8 Thomas Martitz 2011-06-13 02:29:33 UTC
(In reply to comment #7)
> 
>  Can you please try :
> 
> 1) Disable onboard audio 
> 2) Un-mute sound device with 
>    alsamixer -c <Card ID#>

1) I cannot disable onboard sound on this laptop, the BIOS has no option for it.
2) Alsamixer says "This sound device does not have any controls." for the HDMI audio, un-muting the onboard intel chip makes no difference.
Comment 9 Alex Deucher 2011-06-13 07:33:48 UTC
Please make sure your kernel has this patch and try again:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=58e73811c85d0c0e74b8d300547bbc9abaf40a38
Comment 10 Thomas Martitz 2011-06-13 07:51:15 UTC
(In reply to comment #9)
> Please make sure your kernel has this patch and try again:
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=58e73811c85d0c0e74b8d300547bbc9abaf40a38

I'm currently running 3.0-rc2 which should have this patch in without success.
Comment 11 Alex Deucher 2011-06-13 07:57:46 UTC
Does your bios setup have an option to enable the discrete card by default?
Comment 12 Thomas Martitz 2011-06-13 08:16:11 UTC
(In reply to comment #11)
> Does your bios setup have an option to enable the discrete card by default?

Yes and no, it has "Switchable" (with the Intel being default) and "Discrete" (only) as options. For the reference, my laptop is a Acer Aspire Timeline 3810TG.

With Discrete selected in the bios, HDMI also output doesn't work (haven't tried radeon.audio=0 but I assume it would work then).

But I notice two difference compared to switchable. First, the HDMI audio device is not listed in the neither gnome-volume-control pavucontrol anymore, even though lsusb and alsamixer do list it. Second, the screen goes off when plugging the HDMI cable in or out or when switching sources to/from HDMI from/to TV on the TV (only switching to a VT and back to X seems to recover this).
Comment 13 Thomas Martitz 2011-06-13 08:18:35 UTC
Created attachment 47904 [details]
dmesg with discrete selected in bios and plugging HDMI cable a few times
Comment 14 Thomas Martitz 2011-06-13 08:18:59 UTC
Created attachment 47905 [details]
Xorg.0.log with discrete selected in bios and plugging HDMI cable a few times
Comment 15 Thomas Martitz 2011-06-14 11:18:28 UTC
I recognized commit 805c22168da76a65c978017d0fe0d59cd048e995.

I interpret that HDMI audio is troublesome on lots of devices, and that disabling it by default means that there's no actual fix in the works?

It's unfortunate, since what I really want is HDMI audio. Is there some hope for me?
Comment 16 Andy Furniss 2011-06-26 03:36:39 UTC
(In reply to comment #15)
> I recognized commit 805c22168da76a65c978017d0fe0d59cd048e995.
> 
> I interpret that HDMI audio is troublesome on lots of devices, and that
> disabling it by default means that there's no actual fix in the works?
> 
> It's unfortunate, since what I really want is HDMI audio. Is there some hope
> for me?

My TV only has issues with audio with some modes - luckily ones I don't need.

You could try changing modes with xrandr.

One complication is that not all of them are likely to be listed with xrandr --verbose, but they should be in Xorg.o.log so you can add them using xrandr like -

xrandr --newmode "1080p24" 74.25  1920 2558 2602 2750  1080 1084 1089 1125 +hsync +vsync
xrandr --addmode DVI-0 "1080p24"

This is just an example for my tv - you'll need to change the connector name and mode timings (listed in Xorg.o.log) to match yours.
Comment 17 Thomas Martitz 2011-06-26 04:24:10 UTC
(In reply to comment #16)

> 
> My TV only has issues with audio with some modes - luckily ones I don't need.
> 
> You could try changing modes with xrandr.
> 
> One complication is that not all of them are likely to be listed with xrandr
> --verbose, but they should be in Xorg.o.log so you can add them using xrandr
> like -
> 
> xrandr --newmode "1080p24" 74.25  1920 2558 2602 2750  1080 1084 1089 1125
> +hsync +vsync
> xrandr --addmode DVI-0 "1080p24"
> 
> This is just an example for my tv - you'll need to change the connector name
> and mode timings (listed in Xorg.o.log) to match yours.

My Xorg.0.log is attached in a previous post. I don't see that it prints anything for my TV. Do you see something?

Of course (I tried nevertheless) your mode doesn't work on mine.
Comment 18 Andy Furniss 2011-06-27 09:01:42 UTC
(In reply to comment #17)

> My Xorg.0.log is attached in a previous post. I don't see that it prints
> anything for my TV. Do you see something?

Oops - I should have checked those.

Testing with my TV turning on while X is already running it mostly doesn't log the TV modes. FWIW it did for me 2/3 times but only when turning off with xrandr, I suspect the time it failed was when I didn'r run xrandr --verbose first.

If I hotplug/turn on, xrandr --verbose shows a subset of modes, I don't get a signal until I select one or use --auto, but Xorg.0.log prints the modes from my monitor at this point, not the TV- strange.

I guess your best chance of getting them logged is to connect and power up the TV and reboot/restart X rather than hot plugging.
Comment 19 Alex Deucher 2011-08-17 11:19:12 UTC
Is this still an issue with a 3.0 kernel?
Comment 20 Thomas Martitz 2011-08-18 01:35:00 UTC
(In reply to comment #19)
> Is this still an issue with a 3.0 kernel?

Well, I reported this issue running on 3.0-rc2. I'd say it's still an issue, since HDMI audio doesn't work. But as this is a known thing it probably doesn't fit this bug anymore. HDMI Video (only) indeed works by default.
Comment 21 Adam Jackson 2018-06-12 19:09:46 UTC
Mass closure: This bug has been untouched for more than six years, and is not
obviously still valid. Please reopen this bug or file a new report if you continue to experience issues with current releases.


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