2015-05-08 20:45:40

by Paul Moore

[permalink] [raw]
Subject: Re: Commit 0e32b39c ("drm/i915: add DP 1.2 MST support (v0.7)") breaking DP audio on T440s

On Fri, Mar 13, 2015 at 11:19 PM, Paul Moore <[email protected]> wrote:
> Ever since v3.17 I've had a problem with displayport audio on my
> system, but until lately I haven't had a chance to bisect the problem.
> After a few rounds I've isolated the buggy commit to 0e32b39c
> ("drm/i915: add DP 1.2 MST support (v0.7)").
>
> Simply put, prior to v3.17 everything worked correctly: audio from my
> system was routed to my monitor via the DP connection and finally out
> to the speakers connected to the monitor. However, starting with
> kernel v3.17 this no longer works. The various PulseAudio tools all
> indicate that the HDMI/DP audio output is unplugged/not-available.
> I've tried a few different xrandr commands found via google and
> manpages but nothing short of reverting to v3.16 solves the problem.
> I'm hoping that someone with more understanding of the Intel graphics
> drivers will be able to make some sense of it all and provide a fix.
> I'm more than happy to provide additional information and test any
> patches you may have.
>
> For reference, my system is a ThinkPad T440s with a "Intel Corporation
> Haswell-ULT Integrated Graphics Controller (rev 0b)" (according to
> lspci) connected to a Dell U3011 via a Gefen DP KVM.

Help?

The problem still exists on v4.0.1 and I know of at least one other
person that has reported the same problem. As I said above, I'm
willing to do any additional debugging/testing needed, I just could
use some help on resolving this as I am definitely not a
X/graphics-driver expert.

-Paul

--
paul moore
http://www.paul-moore.com


2015-05-11 07:58:26

by Jani Nikula

[permalink] [raw]
Subject: Re: [Intel-gfx] Commit 0e32b39c ("drm/i915: add DP 1.2 MST support (v0.7)") breaking DP audio on T440s

On Fri, 08 May 2015, Paul Moore <[email protected]> wrote:
> On Fri, Mar 13, 2015 at 11:19 PM, Paul Moore <[email protected]> wrote:
>> Ever since v3.17 I've had a problem with displayport audio on my
>> system, but until lately I haven't had a chance to bisect the problem.
>> After a few rounds I've isolated the buggy commit to 0e32b39c
>> ("drm/i915: add DP 1.2 MST support (v0.7)").
>>
>> Simply put, prior to v3.17 everything worked correctly: audio from my
>> system was routed to my monitor via the DP connection and finally out
>> to the speakers connected to the monitor. However, starting with
>> kernel v3.17 this no longer works. The various PulseAudio tools all
>> indicate that the HDMI/DP audio output is unplugged/not-available.
>> I've tried a few different xrandr commands found via google and
>> manpages but nothing short of reverting to v3.16 solves the problem.
>> I'm hoping that someone with more understanding of the Intel graphics
>> drivers will be able to make some sense of it all and provide a fix.
>> I'm more than happy to provide additional information and test any
>> patches you may have.
>>
>> For reference, my system is a ThinkPad T440s with a "Intel Corporation
>> Haswell-ULT Integrated Graphics Controller (rev 0b)" (according to
>> lspci) connected to a Dell U3011 via a Gefen DP KVM.
>
> Help?
>
> The problem still exists on v4.0.1 and I know of at least one other
> person that has reported the same problem. As I said above, I'm
> willing to do any additional debugging/testing needed, I just could
> use some help on resolving this as I am definitely not a
> X/graphics-driver expert.

Hmm, I never received your first mail.

Apparently audio on DP MST is problematic, and the debugging may get a
bit involved. Please file a bug at [1] so we don't clutter the lists
with logs etc. Please enable drm.debug=14 module parameter and attach
(to the bug) dmesg all the way from boot to trying audio on the monitor.

BR,
Jani.


>
> -Paul
>
> --
> paul moore
> http://www.paul-moore.com
> _______________________________________________
> Intel-gfx mailing list
> [email protected]
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

--
Jani Nikula, Intel Open Source Technology Center

2015-05-11 07:59:46

by Jani Nikula

[permalink] [raw]
Subject: Re: [Intel-gfx] Commit 0e32b39c ("drm/i915: add DP 1.2 MST support (v0.7)") breaking DP audio on T440s

On Mon, 11 May 2015, Jani Nikula <[email protected]> wrote:
> On Fri, 08 May 2015, Paul Moore <[email protected]> wrote:
>> On Fri, Mar 13, 2015 at 11:19 PM, Paul Moore <[email protected]> wrote:
>>> Ever since v3.17 I've had a problem with displayport audio on my
>>> system, but until lately I haven't had a chance to bisect the problem.
>>> After a few rounds I've isolated the buggy commit to 0e32b39c
>>> ("drm/i915: add DP 1.2 MST support (v0.7)").
>>>
>>> Simply put, prior to v3.17 everything worked correctly: audio from my
>>> system was routed to my monitor via the DP connection and finally out
>>> to the speakers connected to the monitor. However, starting with
>>> kernel v3.17 this no longer works. The various PulseAudio tools all
>>> indicate that the HDMI/DP audio output is unplugged/not-available.
>>> I've tried a few different xrandr commands found via google and
>>> manpages but nothing short of reverting to v3.16 solves the problem.
>>> I'm hoping that someone with more understanding of the Intel graphics
>>> drivers will be able to make some sense of it all and provide a fix.
>>> I'm more than happy to provide additional information and test any
>>> patches you may have.
>>>
>>> For reference, my system is a ThinkPad T440s with a "Intel Corporation
>>> Haswell-ULT Integrated Graphics Controller (rev 0b)" (according to
>>> lspci) connected to a Dell U3011 via a Gefen DP KVM.
>>
>> Help?
>>
>> The problem still exists on v4.0.1 and I know of at least one other
>> person that has reported the same problem. As I said above, I'm
>> willing to do any additional debugging/testing needed, I just could
>> use some help on resolving this as I am definitely not a
>> X/graphics-driver expert.
>
> Hmm, I never received your first mail.
>
> Apparently audio on DP MST is problematic, and the debugging may get a
> bit involved. Please file a bug at [1] so we don't clutter the lists
> with logs etc. Please enable drm.debug=14 module parameter and attach
> (to the bug) dmesg all the way from boot to trying audio on the monitor.
>
> BR,
> Jani.

[1] https://bugs.freedesktop.org/enter_bug.cgi?product=DRI&component=DRM/Intel



>
>
>>
>> -Paul
>>
>> --
>> paul moore
>> http://www.paul-moore.com
>> _______________________________________________
>> Intel-gfx mailing list
>> [email protected]
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Jani Nikula, Intel Open Source Technology Center

--
Jani Nikula, Intel Open Source Technology Center

2015-05-11 08:06:46

by David Airlie

[permalink] [raw]
Subject: Re: [Intel-gfx] Commit 0e32b39c ("drm/i915: add DP 1.2 MST support (v0.7)") breaking DP audio on T440s




----- Original Message -----
> From: "Jani Nikula" <[email protected]>
> To: "Paul Moore" <[email protected]>, "Dave Airlie" <[email protected]>, [email protected]
> Cc: "Daniel Gultsch" <[email protected]>, [email protected]
> Sent: Monday, 11 May, 2015 6:01:49 PM
> Subject: Re: [Intel-gfx] Commit 0e32b39c ("drm/i915: add DP 1.2 MST support (v0.7)") breaking DP audio on T440s
>
> On Mon, 11 May 2015, Jani Nikula <[email protected]> wrote:
> > On Fri, 08 May 2015, Paul Moore <[email protected]> wrote:
> >> On Fri, Mar 13, 2015 at 11:19 PM, Paul Moore <[email protected]> wrote:
> >>> Ever since v3.17 I've had a problem with displayport audio on my
> >>> system, but until lately I haven't had a chance to bisect the problem.
> >>> After a few rounds I've isolated the buggy commit to 0e32b39c
> >>> ("drm/i915: add DP 1.2 MST support (v0.7)").
> >>>
> >>> Simply put, prior to v3.17 everything worked correctly: audio from my
> >>> system was routed to my monitor via the DP connection and finally out
> >>> to the speakers connected to the monitor. However, starting with
> >>> kernel v3.17 this no longer works. The various PulseAudio tools all
> >>> indicate that the HDMI/DP audio output is unplugged/not-available.
> >>> I've tried a few different xrandr commands found via google and
> >>> manpages but nothing short of reverting to v3.16 solves the problem.
> >>> I'm hoping that someone with more understanding of the Intel graphics
> >>> drivers will be able to make some sense of it all and provide a fix.
> >>> I'm more than happy to provide additional information and test any
> >>> patches you may have.
> >>>
> >>> For reference, my system is a ThinkPad T440s with a "Intel Corporation
> >>> Haswell-ULT Integrated Graphics Controller (rev 0b)" (according to
> >>> lspci) connected to a Dell U3011 via a Gefen DP KVM.
> >>
> >> Help?
> >>
> >> The problem still exists on v4.0.1 and I know of at least one other
> >> person that has reported the same problem. As I said above, I'm
> >> willing to do any additional debugging/testing needed, I just could
> >> use some help on resolving this as I am definitely not a
> >> X/graphics-driver expert.
> >
> > Hmm, I never received your first mail.
> >
> > Apparently audio on DP MST is problematic, and the debugging may get a
> > bit involved. Please file a bug at [1] so we don't clutter the lists
> > with logs etc. Please enable drm.debug=14 module parameter and attach
> > (to the bug) dmesg all the way from boot to trying audio on the monitor.
> >
>


I started looking at this today, the audio driver needs serious work to
make this happen, I'm trying to investigate how much work that is.

Dave.

2015-05-12 12:54:29

by Paul Moore

[permalink] [raw]
Subject: Re: [Intel-gfx] Commit 0e32b39c ("drm/i915: add DP 1.2 MST support (v0.7)") breaking DP audio on T440s

On Monday, May 11, 2015 04:06:37 AM David Airlie wrote:
> ----- Original Message -----
> > From: "Jani Nikula" <[email protected]>
> > To: "Paul Moore" <[email protected]>, "Dave Airlie"
> > <[email protected]>, [email protected] Cc: "Daniel
> > Gultsch" <[email protected]>, [email protected] Sent: Monday,
> > 11 May, 2015 6:01:49 PM
> > Subject: Re: [Intel-gfx] Commit 0e32b39c ("drm/i915: add DP 1.2 MST
> > support (v0.7)") breaking DP audio on T440s>
> > On Mon, 11 May 2015, Jani Nikula <[email protected]> wrote:
> > > On Fri, 08 May 2015, Paul Moore <[email protected]> wrote:
> > >> On Fri, Mar 13, 2015 at 11:19 PM, Paul Moore wrote:
> > >>> Ever since v3.17 I've had a problem with displayport audio on my
> > >>> system, but until lately I haven't had a chance to bisect the problem.
> > >>> After a few rounds I've isolated the buggy commit to 0e32b39c
> > >>> ("drm/i915: add DP 1.2 MST support (v0.7)").
> > >>>
> > >>> Simply put, prior to v3.17 everything worked correctly: audio from my
> > >>> system was routed to my monitor via the DP connection and finally out
> > >>> to the speakers connected to the monitor. However, starting with
> > >>> kernel v3.17 this no longer works. The various PulseAudio tools all
> > >>> indicate that the HDMI/DP audio output is unplugged/not-available.
> > >>> I've tried a few different xrandr commands found via google and
> > >>> manpages but nothing short of reverting to v3.16 solves the problem.
> > >>> I'm hoping that someone with more understanding of the Intel graphics
> > >>> drivers will be able to make some sense of it all and provide a fix.
> > >>> I'm more than happy to provide additional information and test any
> > >>> patches you may have.
> > >>>
> > >>> For reference, my system is a ThinkPad T440s with a "Intel Corporation
> > >>> Haswell-ULT Integrated Graphics Controller (rev 0b)" (according to
> > >>> lspci) connected to a Dell U3011 via a Gefen DP KVM.
> > >>
> > >> Help?
> > >>
> > >> The problem still exists on v4.0.1 and I know of at least one other
> > >> person that has reported the same problem. As I said above, I'm
> > >> willing to do any additional debugging/testing needed, I just could
> > >> use some help on resolving this as I am definitely not a
> > >> X/graphics-driver expert.
> > >
> > > Hmm, I never received your first mail.
> > >
> > > Apparently audio on DP MST is problematic, and the debugging may get a
> > > bit involved. Please file a bug at [1] so we don't clutter the lists
> > > with logs etc. Please enable drm.debug=14 module parameter and attach
> > > (to the bug) dmesg all the way from boot to trying audio on the monitor.
> > >
>
> I started looking at this today, the audio driver needs serious work to
> make this happen, I'm trying to investigate how much work that is.

Hi Dave, Jani,

Thanks for take a look at this, I appreciate it. It looks like the
FreeDesktop BZ #89895 is the same problem I'm having so I added my information
to that BZ. Let me know if there is anything else I can do to help.

* https://bugs.freedesktop.org/show_bug.cgi?id=89895

-Paul

--
paul moore
http://www.paul-moore.com