On 11/09/15 13:38, Thierry Reding wrote:

* PGP Signed by an unknown key

On Fri, Sep 11, 2015 at 11:39:01AM +0100, Jon Hunter wrote:

quoted

Hi Kevin,

On 10/09/15 22:29, Kevin Hilman wrote:

[snip]

quoted

Since there is no movement on this, and jetson hasn't been boot for
multi_v7_defconfig for a while[1], I think it's time to undo the
option causing this problem[2] so that v4.3 will actually boot on the
jetson.

Unless I hear a good reason otherwise, I'll be posting a patch to
disable the HDA related options in multi_v7_defconfig.

So curiosity got the better of this cat, as to why we are not seeing
this ;-)

The main difference I see between the tegra_defconfig and 
multi_v7_defconfig is all the sound drivers are modules (including 
this one).

So trying a quick modprobe of the hda-tegra driver I do see it hang ...

/ # modprobe snd-hda-tegra
[  625.213864] snd_hda_tegra: Unknown symbol azx_probe_codecs (err 0)
[  625.220215] snd_hda_tegra: Unknown symbol azx_init_streams (err 0)
[  625.226480] snd_hda_tegra: Unknown symbol azx_stop_all_streams (err 0)
[  625.233168] snd_hda_tegra: Unknown symbol azx_bus_init (err 0)
[  625.239062] snd_hda_tegra: Unknown symbol azx_free_streams (err 0)
[  625.245314] snd_hda_tegra: Unknown symbol azx_init_chip (err 0)
[  625.251321] snd_hda_tegra: Unknown symbol snd_hda_set_power_save (err 0)
[  625.258081] snd_hda_tegra: Unknown symbol azx_stop_chip (err 0)
[  625.264078] snd_hda_tegra: Unknown symbol azx_codec_configure (err 0)
[  625.270607] snd_hda_tegra: Unknown symbol azx_interrupt (err 0)
[  840.117528] INFO: task modprobe:137 blocked for more than 120 seconds.
[  840.124192]       Not tainted 4.2.0-next-20150909-40826-gb799053 #1
[  840.130584] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  840.138540] modprobe        D c09ac3a4     0   137     82 0x00000000
[  840.145123] [<c09ac3a4>] (__schedule) from [<c09ac838>] (schedule+0x34/0x98)
[  840.152310] [<c09ac838>] (schedule) from [<c09acaac>] (schedule_preempt_disabled+0xc/0x10)
[  840.160734] [<c09acaac>] (schedule_preempt_disabled) from [<c09adeec>] (__mutex_lock_slowpath+0x9c/0x150)
[  840.170458] [<c09adeec>] (__mutex_lock_slowpath) from [<c09adfec>] (mutex_lock+0x4c/0x50)
[  840.178807] [<c09adfec>] (mutex_lock) from [<c062999c>] (__driver_attach+0x44/0x90)
[  840.186627] [<c062999c>] (__driver_attach) from [<c0627fcc>] (bus_for_each_dev+0x54/0x88)
[  840.194966] [<c0627fcc>] (bus_for_each_dev) from [<c0628f88>] (bus_add_driver+0xe4/0x1f0)
[  840.203305] [<c0628f88>] (bus_add_driver) from [<c062a1d0>] (driver_register+0x78/0xf4)
[  840.211475] [<c062a1d0>] (driver_register) from [<c020ac04>] (do_one_initcall+0x80/0x1d0)
[  840.219818] [<c020ac04>] (do_one_initcall) from [<c02c8abc>] (do_init_module+0x58/0x354)
[  840.228081] [<c02c8abc>] (do_init_module) from [<c02afae8>] (load_module+0x17e0/0x1d8c)
[  840.236258] [<c02afae8>] (load_module) from [<c02b016c>] (SyS_init_module+0xd8/0x138)
[  840.244260] [<c02b016c>] (SyS_init_module) from [<c0210b00>] (ret_fast_syscall+0x0/0x3c)

Adding some debug it appears to hang on snd-hda-codec-hdmi  (the following show
the order in which modules are being loaded) ...

/ # modprobe snd-hda-tegra
[   22.450276] snd_hda_tegra: err = -2
[   22.484535] soundcore: err = 0
[   22.488964] snd: err = 0
[   22.493242] snd_timer: err = 0
[   22.498380] snd_pcm: err = 0
[   22.502479] snd_hda_core: err = 0
[   22.508337] snd_hda_codec: err = 0
[   22.513386] snd_hda_tegra: err = 0
[   22.740216] snd_hda_codec_hdmi: err = 0

[hangs here]

However, if I do the following, this works ...

/ # modprobe snd-hda-codec-hdmi
/ # modprobe snd-hda-tegra

So it implies that snd-hda-codec-hdmi needs to be loaded first otherwise it hangs.

Thierry, any thoughts?

I can't reproduce this. Booting multi_v7_defconfig on my setup works
just fine. I don't ever see snd-hda-codec-hdmi being probed, but then
probing it manually works fine. No hangs.

To be clear, booting multi_v7_defconfig works just fine for me too and
has been working fine for months. However, the reason I am not seeing
the issue Kevin and Tyler are reporting is because I never attempt to
"modprobe snd-hda-tegra" after boot. If I do then I see a hang. So I
believe the only reason we don't see this is because their setup is
loading modules.

Cheers
Jon