Bug 52181

Summary: soundcard device of Acer aspire one AO725 not supported
Product: Drivers Reporter: Francesco Muzio (muziofg)
Component: Sound(ALSA)Assignee: Jaroslav Kysela (perex)
Status: NEEDINFO ---    
Severity: high CC: florian, mirh, tiwai
Priority: P1    
Hardware: x86-64   
OS: Linux   
Kernel Version: 3.7.1 Subsystem:
Regression: No Bisected commit-id:
Attachments: a lot of outputs of alsa-info.sh
another output of alsa-info.sh
alsa-info output for a boot with snd_hda_intel index=1,0 enable_msi=0
Test patch
dmesg output after a suspend to ram
alsa-info.sh output before and after a suspend to ram
Test fix patch for codec stalls
dmesg output after patch submitted on comment #24
Fix patch
dmesg output after patch attachment 124291
Better fix patch
dmesg output of booting kernel patched with attachment 125781
patch_realtek.c with alc269_fill_coef() modified
dmesg output with AC plugged
dmesg output without AC plugged
dmesg output without AC plugged
Check return value before COEF write for ALC269 variants
dmesg output without AC plugged

Description Francesco Muzio 2013-01-02 20:58:32 UTC
I wrote here because the website to submit bugs, https://bugtrack.alsa-project.org/alsa-bug/ reltive to Alsa drivers seems to be not reachable.

I have an Acer aspire one AO725 netbook with a soundcard device not well supported. I have tried the latest kernel 3.7 available on debian's experimental branch and my devices (one HDMI and one Analog)  are both recognized as "HD-Audio Generic" by snd_hda_intel kernel module. 

if I run the command
speaker-test -Dplug:front -c2 -twav
I hear only an infinite "front front front front" loop

I have seen that the analog device works well if I load snd_hda_intel with the parameter model=acer-aspire and I would to see it as a default choice.

Also, I would to see this devices under another name because some mixer software, like kmix (part of KDE) seems to confuse the two devices (analog and HDMI) and to recognize the HDMI as a default.  I have solved this problem by disabling HDMI Audio from bios. (but due to bios limitation, other users couldn't  disable it)


this is the output of alsa-info.sh with HDMI disabled 
http://www.alsa-project.org/db/?f=5cfc1eb4ddea5639da838e44c7575537fcf8c96a

and this is my lspci -nn with HDMI Audio enabled ( the PCI ID of the analog device is  1022:780b )

00:00.0 Host bridge [0600]: Advanced Micro Devices [AMD] Family 14h Processor Root Complex [1022:1510]
00:01.0 VGA compatible controller [0300]: Advanced Micro Devices [AMD] nee ATI Device [1002:980a]
00:01.1 Audio device [0403]: Advanced Micro Devices [AMD] nee ATI Wrestler HDMI Audio [Radeon HD 6250/6310] [1002:1314]
00:04.0 PCI bridge [0604]: Advanced Micro Devices [AMD] Family 14h Processor Root Port [1022:1512]
00:05.0 PCI bridge [0604]: Advanced Micro Devices [AMD] Family 14h Processor Root Port [1022:1513]
00:10.0 USB controller [0c03]: Advanced Micro Devices [AMD] FCH USB XHCI Controller [1022:7812] (rev 03)
00:11.0 SATA controller [0106]: Advanced Micro Devices [AMD] FCH SATA Controller [AHCI mode] [1022:7801]
00:12.0 USB controller [0c03]: Advanced Micro Devices [AMD] FCH USB OHCI Controller [1022:7807] (rev 11)
00:12.2 USB controller [0c03]: Advanced Micro Devices [AMD] FCH USB EHCI Controller [1022:7808] (rev 11)
00:13.0 USB controller [0c03]: Advanced Micro Devices [AMD] FCH USB OHCI Controller [1022:7807] (rev 11)
00:13.2 USB controller [0c03]: Advanced Micro Devices [AMD] FCH USB EHCI Controller [1022:7808] (rev 11)
00:14.0 SMBus [0c05]: Advanced Micro Devices [AMD] FCH SMBus Controller [1022:780b] (rev 14)
00:14.2 Audio device [0403]: Advanced Micro Devices [AMD] FCH Azalia Controller [1022:780d] (rev 01)
00:14.3 ISA bridge [0601]: Advanced Micro Devices [AMD] FCH LPC Bridge [1022:780e] (rev 11)
00:14.4 PCI bridge [0604]: Advanced Micro Devices [AMD] FCH PCI Bridge [1022:780f] (rev 40)
00:18.0 Host bridge [0600]: Advanced Micro Devices [AMD] Family 12h/14h Processor Function 0 [1022:1700] (rev 43)
00:18.1 Host bridge [0600]: Advanced Micro Devices [AMD] Family 12h/14h Processor Function 1 [1022:1701]
00:18.2 Host bridge [0600]: Advanced Micro Devices [AMD] Family 12h/14h Processor Function 2 [1022:1702]
00:18.3 Host bridge [0600]: Advanced Micro Devices [AMD] Family 12h/14h Processor Function 3 [1022:1703]
00:18.4 Host bridge [0600]: Advanced Micro Devices [AMD] Family 12h/14h Processor Function 4 [1022:1704]
00:18.5 Host bridge [0600]: Advanced Micro Devices [AMD] Family 12h/14h Processor Function 6 [1022:1718]
00:18.6 Host bridge [0600]: Advanced Micro Devices [AMD] Family 12h/14h Processor Function 5 [1022:1716]
00:18.7 Host bridge [0600]: Advanced Micro Devices [AMD] Family 12h/14h Processor Function 7 [1022:1719]
01:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller [10ec:8136] (rev 05)
02:00.0 Network controller [0280]: Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller [14e4:4727] (rev 01)


I hope to be helpful
Francesco Muzio
Comment 1 Francesco Muzio 2013-01-05 16:14:26 UTC
Also with my solution sometimes  the problem reappears, and when it happens i see this error in the dmesg output

hda-intel: azx_get_response timeout, switching to polling mode: last cmd=0x00df000d
Comment 2 Francesco Muzio 2013-01-09 19:35:34 UTC
damn, options added to a module in the file /etc/modules doesn't works 

now I have added the options in a .conf file on /etc/modprobe.d/ directory

options snd-hda-intel model=acer-aspire probe-mask=1

and seems to work well to each boot

If you request more information/debug please ask me
Comment 3 Takashi Iwai 2013-01-10 14:31:30 UTC
Could you give alsa-info.sh outputs at both working and non-working states, and attach to this bugzilla?

But I'm wondering how model=acer-aspire option works for you.  This codec chip doesn't have this model string, so it shouldn't change anything...
Comment 4 Francesco Muzio 2013-01-11 18:14:20 UTC
Created attachment 91031 [details]
a lot of outputs of alsa-info.sh

I have run the alsa-info.sh scripts many times

For simplicity, from now on I will call the problem that afflicts me (confirmed by the presence of the message "hda-intel: azx_get_response timeout, switching to polling mode ....") "The problem"

I have a lot of outputs:

1) alsa-info_HDMI_Enabled_NotWork.txt -> contains the output after a boot with Analog and HDMI devices both enabled. In this situation speaker-test is unable to work because the HDMI device is enumerated/recognized before the Analog.
But I haven't seen any "azx_get_response timeout" in the dmesg

the follow outputs are taken with HIDMI disabled by bios 

2) alsa-info_ko_HDMI_Disabled_noParameter.txt -> contains the output after a boot with snd-hda-intel loaded without parameter. The problem occurred again

3) alsa-info_ko_HDMI_Disabled_OnlyMaskParameterSet.txt -> contains the output after a boot with snd-hda-intel loaded with probe-mask=1. The problem occurred again

4) alsa-info_ok_HDMI_Disabled_ModelAndMaskParameterSet.txt -> contains the output after a boot with snd-hda-intel loaded with probe-mask=1 and model=acer-aspire. The problem isn't occurred

5) alsa-info_ok_HDMI_Disabled_ModelAndMaskParameterSet_2nd_boot.txt -> contains the output after a boot with snd-hda-intel loaded with probe-mask=1 and model=acer-aspire. The problem isn't occurred

6) alsa-info_ok_HDMI_Disabled_noParameter.txt -> contains the output after a boot with snd-hda-intel loaded without parameter. The problem isn't occurred


I have uploaded the output of two boots with "snd-hda-intel model=acer-aspire probe-mask=1" used because sometimes the system assigns to the device the irq 45 or the irq 46, but in both situation the device can work.


I have tried the solution with only probe-mask parameter set, but it doesn't work. 
For now the snd-hda-intel model=acer-aspire probe-mask=1 modprobe solution seems to work and I haven't seen yet the azx_get_response in the dmesg output. 


I have attached a tar.gz file with all 6 outptus just described.

Hope to be helpful
Comment 5 Francesco Muzio 2013-01-11 21:22:01 UTC
Created attachment 91041 [details]
another output of alsa-info.sh

I have to correct myself, tonight I have found the error:

hda-intel: azx_get_response timeout, switching to polling mode: last cmd=0x003b8000

in the dmesg output, when the module snd-hda-intel has been loaded with both parameters....

I have attached also this output, taken with alsa-info.sh, named alsa-info_ko_HDMI_Disabled_ModelAndMaskParameterSet.txt
Comment 6 Takashi Iwai 2013-01-13 09:19:13 UTC
You can pass index=1,0 option to snd-hda-intel to swap HDMI and analog devices.
(But this will screw up the index again when only the analog is loaded, as it assumes there are two instances.)

Since the problem is related with the interrupt, try to pass enable_msi=0 option, to.

Also, the model option you passed is maybe just a coincident.  I guess the string value doesn't matter, and you'll get the same effect even if you pass a string like model=foobar.
Comment 7 Francesco Muzio 2013-01-13 15:28:14 UTC
Created attachment 91111 [details]
alsa-info output for a boot with snd_hda_intel index=1,0 enable_msi=0

After the firsts boots I can tell "seems to work" but I must to boot my machine many times to be sure

I have attached the alsa-info output of my last boot.



still remains a little problem (also occurs when the 2 Audio devices are enabled but not swapped) 

when I (or the system) run the command:

aslactl restore

this warning appears on the stdout: 

alsactl: set_control:1464: Cannot write control '3:3:0:Playback Channel Map:0' : File descriptor in bad state

Maybe this problem is not related to the kernel, in any case I have reported it

Thanks for your support
Comment 8 Francesco Muzio 2013-01-17 19:08:57 UTC
Another question

This netbook has a combo jack  for microphone and headphones. It works on windows 8 but not on linux.

When I put the combo jack the audio is redirected to the headphones but the internal microphone continues to record instead of the external.

How I can debug/solve this issue ? snd-hda-intel it's able to support a combo jack solution?
Comment 9 Takashi Iwai 2013-01-18 07:26:09 UTC
The combo jack on an Acer laptop was already supported in 3.8 kernel, but it's not applied to AO725 as default.

Try the patch below on the latest Linus tree (or 3.8-rc4).
Comment 10 Takashi Iwai 2013-01-18 07:27:04 UTC
Created attachment 91441 [details]
Test patch
Comment 11 Francesco Muzio 2013-01-18 23:29:51 UTC
I have applied the patch to the latest kernel (3.8-rc4) 

I'm happy to tell "It works!"

And I have seen that in the latest version there are no warning when I run "alsactl restore"

Very happy, thank you!
Comment 12 Takashi Iwai 2013-01-19 11:20:29 UTC
OK, the patch is merged to sound git tree.  It'll be included in the next pull request for 3.8-rc5.

Thanks for quick tests.
Comment 13 Francesco Muzio 2013-01-25 23:42:50 UTC
Created attachment 91811 [details]
dmesg output after a suspend to ram

Unfortunately I must reopen this bug report, because the "azx_get_response timeout" problem (the main problem) still appears after a suspend-to-ram

I have attached the dmesg log taken after a suspend-to-ram/resume action
Comment 14 Florian Mickler 2013-01-26 10:49:50 UTC
A patch referencing this bug report has been merged in Linux v3.8-rc5:

commit ec50b4cea63fdcd1f1c428b93a47986d74c244b8
Author: Takashi Iwai <tiwai@suse.de>
Date:   Sat Jan 19 12:17:54 2013 +0100

    ALSA: hda - Add fixup for Acer AO725 laptop
Comment 15 Francesco Muzio 2013-01-26 12:10:10 UTC
Sorry, there was a little bit of confusion.

The patch that you are indicated is related to the external microphone bug.

In this bug report I have reported 2 bugs: one as been patched (the external mic) but the other isn't solved. 
I was in testing with the enable_msi=0 proposed solution. But every time I put my netbook in suspend-to-ram state, at the resume the suond doesn't work correctly.
Comment 16 Francesco Muzio 2013-01-26 18:32:19 UTC
My conclusions:

when I boot with snd_hda_intel index=1,0 enable_msi=0 the sound works until I don't suspend to ram the machine (every time)

when I boot with snd_hda_intel index=1,0 enable_msi=1 the sound maybe not works, but if it works after the boot, works also after a suspend to ram
Comment 17 Takashi Iwai 2013-01-27 09:36:51 UTC
Are you sure about it?  It doesn't explain why it makes such a difference.
Does this happen also with hibernation?

Also, what kernel are you testing?  If it's 3.8-rc, please use 3.8-rc5.  Until rc4 there is a known bug regarding the resume.

Note that "azx_response timeout" itself isn't a big problem.  It may happen on many machines and mostly harmless (unless going to the single_cmd mode).  So, you can't judge the problem only from that message.

If a PCM stream doesn't work (i.e. repeating), check whether the interrupt count changes via any sound access, i.e. PCM stream playback/capture or a mixer value change.  If the irq count doesn't change, it's a problem of the PCI controller.

If you face a silent PCM output instead, this might be a different problem.
Comment 18 Francesco Muzio 2013-01-27 14:01:33 UTC
the problem is always the "repeating", reported in the description of this bug report 

And no, the bug doesn't happens if the netbook is suspended to disk.  



I have used the version 3.7.1 of kernel available in debian experimental branch because this machine has a CPU at 1GHZ and it's a pain to compile an entire kernel. So I have compiled it (3.8-rc4 + patch) for only test your patch with a "mutilated" kernel (eg. no wireless) for reduce the compile time, but it's a kernel unusable in other context.

If it's necessary I can recompile the latest version (v3.8-rc5) to see what happens with it. But it takes time...
Comment 19 Francesco Muzio 2013-01-27 14:09:04 UTC
Created attachment 91951 [details]
alsa-info.sh output before and after a suspend to ram

I have attached the alsa-info.sh output before and after a suspend to ram  

I was going to forget: 
yes, I know that the "azx_response timeout" warning is mostly harmless, but on my netbook occurs always when the audio driver stops to work correctly
Comment 20 Takashi Iwai 2013-01-28 09:07:12 UTC
As mentioned, the most certain way is to check whether the interrupt counts increase.  See /proc/interrupts and check whether the number for the audio driver changes when you do something for the audio (suppose it's non-shared irq).

If it's an interrupt issue, the culprit is more likely in the deeper level, e.g. PCI core, ACPI, etc.
(The fact that only S3 affects implies it, too...)
Comment 21 Francesco Muzio 2013-02-02 18:13:28 UTC
I have tried the last kernel (v3.8-rc6) 

The problem still exists when I suspend to ram my netbook 

The interruputs changes frequently during a session of use.  (fetched with cat /proc/interrupts | grep snd)


I must add a detail: 
I don't use pulseaudio, every software dialogs directly with ALSA. 
When the problem occurs softwares like speaker-test, mpg123, VLC freeze themselves.
KDE system sound and some KDE players (like dragon player)  seems to works correctly again this event. On debian it's running a version 4.8.x of KDE with the phonon-gstreamer backend installed) 

How can I to investigate again about this bug ?
Comment 22 Francesco Muzio 2013-02-09 22:38:00 UTC
The problem occurs also if I disable the "multicore support" from the BIOS
Comment 23 Takashi Iwai 2013-11-29 08:03:28 UTC
Does the problem still happen with 3.12 kernel?

If it is, this might be due to some codec verb accesses that this codec doesn't like.  In that case, try the patch below.

If the patch helped, try to narrow down the disabled codes by the patch.  The second ifdef chunk should be harmless.  Either the first one or the third one (or both) hits the problem...
Comment 24 Takashi Iwai 2013-11-29 08:06:06 UTC
Created attachment 116621 [details]
Test fix patch for codec stalls
Comment 25 Francesco Muzio 2014-01-26 16:31:17 UTC
I'm sorry for the long delay. The bug doesn't happens if I use the pulseaudio sound server, so I am using the pulseaudio.

But in the recent kernel (v3.12 and v3.13) a strange message is appeared on the dmesg, this message in repeated many times:

hda-codec: out of range cmd 0:20:400:ffffffff

The audio works well, but I don't understand what means and if this message is important.

see the attachment 123391 [details] who contains the dmesg of my AO725 booted with kernel v3.13
Comment 26 Takashi Iwai 2014-01-27 08:47:31 UTC
It means some wrong COEF write has been performed, which is likely the result of the wrong COEF read.  It might be the cause of the codec communication stall, so it can be a serious problem.

Please try the patch in comment 24 and see whether this message is gone.
Comment 27 Francesco Muzio 2014-02-01 22:16:55 UTC
Created attachment 124131 [details]
dmesg output after patch submitted on comment #24

yes, with the attachment 116621 [details] the "hda_codec: out of range cmd..." messages are gone.

see the dmesg
Comment 28 Takashi Iwai 2014-02-02 08:32:59 UTC
OK, could you check which #if 0 actually fixes the issue?  There are three ifdefs, and likely only one of them is effective.
My bet is the first one (around alc269_fill_coef() call.)
Comment 29 Francesco Muzio 2014-02-02 21:11:10 UTC
I have booted my netbook with three diffent patched kernel, each with an only #if block applied.

With the first #if the message "hda-codec: out of range cmd....." is not showed

With the second #if the message "hda-codec: out of range cmd....." is showed many times and the during the printing of more "hda-codec: out of range cmd 0:20:400:ffffffff" the kernel seems to be stalled, then boot normally.

With the third #if the message "hda-codec: out of range cmd....." is showed many times but the machine boot normally as running a standard unpatched kernel
Comment 30 Takashi Iwai 2014-02-03 09:01:30 UTC
Thanks for quick tests.  So my guess seems correct; the first chunk is the culprit.

Could you try the patch below instead of the previous one?  If this is confirmed to work, I'm going to merge it to the upstream.
Comment 31 Takashi Iwai 2014-02-03 09:02:54 UTC
Created attachment 124291 [details]
Fix patch
Comment 32 Francesco Muzio 2014-02-04 21:20:33 UTC
Created attachment 124521 [details]
dmesg output after patch attachment 124291 [details]

I have tryed your attachment 124291 [details] as a patch and works. 

See my dmesg 

Thanks
Comment 33 Takashi Iwai 2014-02-12 16:46:41 UTC
It turned out that the patch brings a problem on other machines with the same codec.  (The output is gone.)
So, this doesn't seem to be specific to the codec but to the machine.

Could you revert the previous fix and try the next one instead, to see whether it still fixes the problem?
Comment 34 Takashi Iwai 2014-02-12 16:47:05 UTC
Created attachment 125781 [details]
Better fix patch
Comment 35 Francesco Muzio 2014-02-12 22:17:37 UTC
Created attachment 125811 [details]
dmesg output of booting kernel patched with attachment 125781 [details]

I have tried this patch but I see some strange behaviour

After log into my user space I have listen VLC plays music 
After few minutes I have tried to connect my combo earphones+microphone but audio seems not working with external earphones. (unpatched 3.13 kernels works) However the external microphone seems to work (audacity bar react when I speak into it).

Also after a logout the "hda-codec:" errors returns (I see it on stdout)

After more connection/disconnection of the audio jack the sounds has stopped working and after the reboot the analog audio devices seems to be disappear! 
But all seems to be returned to standard behaviour after a cold boot with older (and unpatched) kernel 3.12 

I have to say, I honestly haven't tried the functionality of the earphones with previous patches. Would I do it ?

The dmesg of the first boot is attached
Comment 36 Takashi Iwai 2014-02-14 20:18:52 UTC
Hrm, OK, then we seem to need some of COEFs, narrowing down the range to disable.

Could you figure out which COEF call triggers the problem?  For example, you can put printk() for each line in alc269_fill_coef() (and its further calls), and see where the problem happens.
Comment 37 Francesco Muzio 2014-02-14 21:16:52 UTC
I know what are the printk() function but I don't think to be able to use it in the right direction.

What do you want to print? What I should use as a parameter for the calls of this function?

Do you want to see the result of this printk() on a unpatched kernel or on the kernel with the (latest) patch?
Comment 38 Francesco Muzio 2014-05-05 21:37:23 UTC
I renew my request: please tell me how to debug the kernel as you mean, where and how I put the printk in the sourcecode.

Also I'm looking a reproducible rule: the messages "hda-codec: out of range cmd ....." are printed only if the netbook is running without the AC power connected
When the netbook is powered from the AC I don't see any messages like "hda-codec: out of range cmd" in the dmesg output
Comment 39 Takashi Iwai 2014-05-06 05:26:13 UTC
Just put a printk() with a unique string at each line of alc269_fill_coef(), e.g.

static void alc269_fill_coef(struct hda_codec *codec)
{
        struct alc_spec *spec = codec->spec;
        int val;

        if (spec->codec_variant != ALC269_TYPE_ALC269VB)
                return;

printk("XXX alc269_fill_coef %d\n", __LINE__);
        if ((alc_get_coef0(codec) & 0x00ff) < 0x015) {
printk("XXX alc269_fill_coef %d\n", __LINE__);
                alc_write_coef_idx(codec, 0xf, 0x960b);
printk("XXX alc269_fill_coef %d\n", __LINE__);
                alc_write_coef_idx(codec, 0xe, 0x8817);
        }

printk("XXX alc269_fill_coef %d\n", __LINE__);
        if ((alc_get_coef0(codec) & 0x00ff) == 0x016) {
printk("XXX alc269_fill_coef %d\n", __LINE__);
                alc_write_coef_idx(codec, 0xf, 0x960b);
printk("XXX alc269_fill_coef %d\n", __LINE__);
                alc_write_coef_idx(codec, 0xe, 0x8814);
....

and check "out of range cmd" error happens at which point.  The last call before the error message is supposed to be the one triggering the error.
Comment 40 Francesco Muzio 2014-05-17 21:50:52 UTC
I'm sorry for the delay

I have made this tests with the latest kernel available on Debian testing (3.14) and I have saved a dmesg output in both cases:

- dmesg_AC: machine booted with AC power plugged in. In this test all seems to work as expected. I have also run VLC with a song and after this action no more output seems to be printed on dmesg

- dmesg_BATT: machine booted without AC power plugged in. In this case "out of range cmd" error happens never but I found a lot of "XXX  alc269_fill_coef" messages.

In the dmesg_BATT please note that after the message

 [  120.378846] XXX alc269_fill_coef 4648

I have running a song with VLC (and the music works)

I have modified the file patch_realtek.c, this file is attached in the next messages. So you can see the line number assigned at any printk.
Comment 41 Francesco Muzio 2014-05-17 21:52:19 UTC
Created attachment 136511 [details]
patch_realtek.c with alc269_fill_coef() modified
Comment 42 Francesco Muzio 2014-05-17 21:53:05 UTC
Created attachment 136521 [details]
dmesg output with AC plugged
Comment 43 Francesco Muzio 2014-05-17 21:53:36 UTC
Created attachment 136531 [details]
dmesg output without AC plugged
Comment 44 Takashi Iwai 2014-05-18 06:22:04 UTC
You have to repeat testing the kernel until you get the problematic state.  Or, it might be a timing issue.  Then gradually reduce the printk's that look OK, and try until you hit the problem again.

In anyway, the only purpose of this test is to identify which command results in the error.  So, without seeing the error, it doesn't help at all, unfortunately.
Comment 45 Francesco Muzio 2014-05-19 20:58:18 UTC
I have commented some lines in the previous patch_realtek.c and I have add a printk at the top of the alc269_fill_coef() function, at line 4598

I have run a kernel where the alc269_fill_coef() function contain the first printk at line 4598 and the last (uncommented) printk at line 4637

In the dmesg I see that the "out of range" errors are printed before a printk at line 4598 and after the last printk at line 4637.

I think that the message has been raised by an istruction outside this function.
Comment 46 Takashi Iwai 2014-05-20 05:48:32 UTC
Then you need to figure out the caller of the error.  For example, put "WARN(1);" line at the error message in make_codec_cmd() in hda_codec.c.  Then it'll give a stack trace like Oops.

After that, try to reduce the command verbs by commenting out or so for identifying the culprit.

But, also note that the error message *might* not be the direct culprit of the bug itself.  It might be a side-effect.  But, this is likely the way to trace the original bug.
Comment 47 Francesco Muzio 2014-05-20 20:58:23 UTC
when I trying to compile the kernel with a "WARN(1);"
line placed between "printk(KERN_ERR "hda-codec:...." and "return ~0;" I get  compilation error. Maybe it require two or more arguments...

I'm not skilled on Linux kernel, but I'm happy to know more on how to debug it

Please explain me how to correctly use the WARN macro.
Comment 48 Francesco Muzio 2014-08-13 12:44:26 UTC
I'm sorry for the delay, but I'm not yet able to debug the problem.

Can you provide me an example to understand how to use the "WARN(1)" or other equivalent mechanisms to correctly debug the bug?

thanks in advance
Comment 49 Takashi Iwai 2014-08-13 13:11:43 UTC
Put like WARN(1, "XXX some message\n")
Comment 50 Francesco Muzio 2014-08-14 13:48:15 UTC
Created attachment 146571 [details]
dmesg output without AC plugged

I have patched the latest stable kernel available (3.16).
I have put a single
WARN(1, "WWW WARN\n");
at the end of the line 205 in the hda_codec.c file (between codec_err() and the return instruction in the make_codec_cmd() function)

the dmesg output is attached

ps: for this test I haven't patched the alc269_fill_coef() function with any printk.
Comment 51 Takashi Iwai 2014-08-14 14:29:07 UTC
What about the patch below?
Comment 52 Takashi Iwai 2014-08-14 14:31:09 UTC
Created attachment 146581 [details]
Check return value before COEF write for ALC269 variants
Comment 53 Francesco Muzio 2014-08-15 13:36:36 UTC
Created attachment 146741 [details]
dmesg output without AC plugged

This patch seems  to work correctly, I have tested it with vlc on pulseaudio.

See the dmesg devoid of error messages