[Letux-kernel] [PATCH 0/8] Get sound playback working on the Pandora again

H. Nikolaus Schaller hns at goldelico.com
Sun Jan 9 18:26:57 CET 2022


Hi Stefan and Grond,


> Am 08.01.2022 um 17:30 schrieb Stefan Leichter <sle85276 at gmx.de>:
> 
> Hello Grond,
> 
> On 07.01.22 23:01, Grond wrote:
>> On Fri, Jan 07, 2022 at 09:17:50PM +0100, Stefan Leichter wrote:
>>> Hi Grond,
>>> 
>>> I can wait longer between the startup an the ssh login, just suggest a duration.
>>> 
>>> If I first login at the console the playback device will appear directly at the first aplay call after the login, even if I did not wait for five minutes after starting the pandora.
>> The reason I mention that it might be a timing issue is that the console
>> login is not very well-coupled to the audio driver stack. It seems
>> really unlikely that logging in on the console actually *causes* sound
>> card probe to succeed. But I would be really interested to see what
>> dmesg looks like after the sound card probe has succeeded. Also, if you
>> could try compiling a kernel with DYNAMIC_DEBUG enabled, you can see all
>> of the ASoC core debug messages, which I've found is really helpful in
>> running down the root cause of why the sound card driver isn't loading.
>> (I would suggest adding dyndbg="file sound/* +fp" to the kernel command
>> line as well.)
>> 
> I don't see anything new in the dmesg output after the console login.

here is what I see when trying to ssh into the pandora while it is booting:

iMac:~ hns$ ssh root at 192.168.0.202 aplay -L
ssh: connect to host 192.168.0.202 port 22: Connection refused
iMac:~ hns$ ssh root at 192.168.0.202 aplay -L
null
    Discard all samples (playback) or generate zero samples (capture)
default:CARD=omap3pandora
    omap3pandora, HiFi Out pcm1773-hifi-0
    Default Audio Device
sysdefault:CARD=omap3pandora
    omap3pandora, HiFi Out pcm1773-hifi-0
    Default Audio Device
dmix:CARD=omap3pandora,DEV=0
    omap3pandora, HiFi Out pcm1773-hifi-0
    Direct sample mixing device
dsnoop:CARD=omap3pandora,DEV=0
    omap3pandora, HiFi Out pcm1773-hifi-0
    Direct sample snooping device
hw:CARD=omap3pandora,DEV=0
    omap3pandora, HiFi Out pcm1773-hifi-0
    Direct hardware device without any conversions
plughw:CARD=omap3pandora,DEV=0
    omap3pandora, HiFi Out pcm1773-hifi-0
    Hardware device with all software conversions
iMac:~ hns$ ssh root at 192.168.0.202 uname -a
Linux letux 5.16.0-rc8-letux+ #7911 SMP PREEMPT Sun Jan 9 16:14:23 CET 2022 armv7l GNU/Linux
iMac:~ hns$ ssh root at 192.168.0.202 dmesg|fgrep 517
[    0.000030] sched_clock: 32 bits at 32kHz, resolution 30517ns, wraps every 65535999984741ns
[   11.474975] omap3pandora-sound omap3pandora-sound: Failed to register sound card: -517
iMac:~ hns$ 

So, yes there is a (temporary) message "Failed to register sound card: -517"
but the sound card is available when the first ssh succeeds (it is refused
initially because the sshd isn't listening on port 22 yet).

I still see the 

[ 2438.947601] ti-soc-thermal 48002524.bandgap: eocz timed out waiting h
[ 2583.399780] omap_i2c 48060000.i2c: timeout waiting on XUDF bit

coming more in bursts - and unclear if it is related to ssh traffic over USB.
The reason why I think about that is that it starts (sometimes) if I run
apt-get update && apt-get upgrade over ssh. Or some git checkout. And stops when done.
Or it may just happen on high processor load.

This all looks like an issue with power management/idling of the processor.
Or some interrupt is blocked and not re-enabled.

BR,
Nikolaus

PS:

[ 1581.203582] ti-soc-thermal 48002524.bandgap: eocz timed out waiting high
can be triggered every now and then by

	while true; do cat /sys/class/thermal/thermal_zone0/temp; done

while
[ 1583.790405] omap_i2c 48060000.i2c: timeout waiting on XUDF bit
can be treiggered sometimes by

	apt-get update

On the other hand, a

	wget -O /dev/null http://download.goldelico.com/letux-debian-rootfs/2021/20210825-jessie-8.11-i386-lxde.tbz

does not.


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