Fwd: in linux 6.3.7-200.fc38.x86_64 goes vlc in time to switch tv channels to zombie-process

Fwd: in linux 6.3.7-200.fc38.x86_64 goes vlc in time to switch tv channels to zombie-process

[Bagas Sanjaya]

Hi,

I notice a regression report on Bugzilla [1]. Quoting from it:

> vmlinuz-6.3.7-200.fc38.x86_64  and vmlinuz-6.3.8-200.fc38.x86_64
> 
> in the switch tv channel to another vlc stay blocked and and the loading of firmware newer ending. power must be switch to off.
> from dmesg:
> 
> dvb-tuner-si2141-a10-01.fw
> dvb-demod-si2168-d60-01.fw 
> firmware version: D 6.0.13
> 
> restart of dvb modules is impossible, They stay working. 
> 
> kernel 6.3.5-200.fc38.x86_64 works  OK. I don't how works kernel 6.3.6-200.fc38.x86_64
> 
> this same error is in vmlinuz-6.3.5-200.fc38.x86_64 and earliers but there is the occurence accesptable.
> 
> listing from 6.3.5 kernel:
> 
> [ 3378.026035] si2168 7-0064: firmware version: D 6.0.13
> [ 3431.891579] si2168 7-0064: downloading firmware from file 'dvb-demod-si2168-d60-01.fw'
> [ 3434.037278] usb 1-4: dvb_usb_v2: 2nd usb_bulk_msg() failed=-110
> [ 3434.037289] si2168 7-0064: firmware download failed -110
> [ 3436.085265] usb 1-4: dvb_usb_v2: usb_bulk_msg() failed=-110
> 
> lsmod |grep dvb
> dvb_usb_dvbsky         32768  2
> dvb_usb_v2             57344  1 dvb_usb_dvbsky
> m88ds3103              49152  1 dvb_usb_dvbsky
> dvb_core              192512  3 dvb_usb_v2,m88ds3103,dvb_usb_dvbsky
> m
> 
> modprobe -r dvb_usb_dvbsky
> modprobe: FATAL: Module dvb_usb_dvbsky is in use.
> 
> ?????? The problem in dvb_usb_dvbsky or firmware ?????   
> 
> The answer from https://bugzilla.rpmfusion.org was:
> 
> If it was working with previous kernel this is likely a kernel regression. 
> please forward to the dvb sub-system maintainers.
> 
> this problen insist a long time (years), but not too horible

See Bugzilla for the full thread and attached dmesg and lsusb.

Thorsten: The reporter can't perform bisection for he has problem
compiling his own vanilla kernel (see comment 8 on the Bugzilla
ticket, albeit with translated make(1) output). Can you take a look on
it?

Anyway, I'm adding it to regzbot (as stable-specific regression
for now):

#regzbot introduced: v6.3.5..v6.3.7 https://bugzilla.kernel.org/show_bug.cgi?id=217566
#regzbot title: switching TV channel causes VLC and firmware loading hang

Thanks.

[1]: https://bugzilla.kernel.org/show_bug.cgi?id=217566

-- 
An old man doll... just what I always wanted! - Clara

Re: Fwd: in linux 6.3.7-200.fc38.x86_64 goes vlc in time to switch tv channels to zombie-process

[Linux regression tracking #update (Thorsten Leemhuis)]

[TLDR: This mail in primarily relevant for Linux kernel regression
tracking. See link in footer if these mails annoy you.]

On 19.06.23 02:24, Bagas Sanjaya wrote:
> 
> I notice a regression report on Bugzilla [1]. Quoting from it:
> [...]
> 
> #regzbot introduced: v6.3.5..v6.3.7 https://bugzilla.kernel.org/show_bug.cgi?id=217566
> #regzbot title: switching TV channel causes VLC and firmware loading hang

#regzbot fix: 7cfab4c9dc09ca3a9d57c187894055a22bdcd
#regzbot ignore-activity

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
--
Everything you wanna know about Linux kernel regression tracking:
https://linux-regtracking.leemhuis.info/about/#tldr
That page also explains what to do if mails like this annoy you.

Re: Fwd: in linux 6.3.7-200.fc38.x86_64 goes vlc in time to switch tv channels to zombie-process

[Hans Verkuil]

On 31/08/2023 11:26, Linux regression tracking #update (Thorsten Leemhuis) wrote:
> [TLDR: This mail in primarily relevant for Linux kernel regression
> tracking. See link in footer if these mails annoy you.]
> 
> On 19.06.23 02:24, Bagas Sanjaya wrote:
>>
>> I notice a regression report on Bugzilla [1]. Quoting from it:
>> [...]
>>
>> #regzbot introduced: v6.3.5..v6.3.7 https://bugzilla.kernel.org/show_bug.cgi?id=217566
>> #regzbot title: switching TV channel causes VLC and firmware loading hang
> 
> #regzbot fix: 7cfab4c9dc09ca3a9d57c187894055a22bdcd
> #regzbot ignore-activity
> 
> Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
> --
> Everything you wanna know about Linux kernel regression tracking:
> https://linux-regtracking.leemhuis.info/about/#tldr
> That page also explains what to do if mails like this annoy you.
> 
> 

From what I can gather from the bugzilla report, whatever the issue was appears
to be resolved or at least improved in later kernels.

I can't find any relevant differences for the dvb-usb-v2/dvbsky/si2168 drivers that
are used here, even if I diff between v6.2.1 and v6.4.1. So either fedora
applied some patch that is not in linux-stable, or the issue is elsewhere,
outside the media subsystem.

Regards,

	Hans

Re: Fwd: in linux 6.3.7-200.fc38.x86_64 goes vlc in time to switch tv channels to zombie-process

[Thorsten Leemhuis]

On 31.08.23 12:35, Hans Verkuil wrote:
> On 31/08/2023 11:26, Linux regression tracking #update (Thorsten Leemhuis) wrote:
>> [TLDR: This mail in primarily relevant for Linux kernel regression
>> tracking. See link in footer if these mails annoy you.]
>>
>> On 19.06.23 02:24, Bagas Sanjaya wrote:
>>>
>>> I notice a regression report on Bugzilla [1]. Quoting from it:
>>> [...]
>>>
>>> #regzbot introduced: v6.3.5..v6.3.7 https://bugzilla.kernel.org/show_bug.cgi?id=217566
>>> #regzbot title: switching TV channel causes VLC and firmware loading hang
>>
>> #regzbot fix: 7cfab4c9dc09ca3a9d57c187894055a22bdcd
>> #regzbot ignore-activity
>>
>> Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
>> --
>> Everything you wanna know about Linux kernel regression tracking:
>> https://linux-regtracking.leemhuis.info/about/#tldr
>> That page also explains what to do if mails like this annoy you.
> 
>>From what I can gather from the bugzilla report, whatever the issue was appears
> to be resolved or at least improved in later kernels.

I'm pretty (but not 100%) sure the initial report in that ticket were
issues caused by a backport of a patch that was reverted later:
https://lore.kernel.org/all/20230609082238.3671398-1-mchehab@kernel.org/

The versions when the problems started and some feedback in the ticket
when things started working again (like
https://bugzilla.kernel.org/show_bug.cgi?id=217566#c15 – 6.3.9 was when
the revert came to 6.3.y) are strong indicators for that.

But yes, more people showed up in the ticket with problems that might or
might not be related to the initial problem and things got confusing. I
told them to report those problems separately. Ideally somebody would
look into that and check if they did, yes, but I chose to ignore things
at that point, as regression tracking is quite hard already and I have
to draw lines somewhere. I often hate that, but otherwise I don't get
much work done. :-/

Ciao, Thorsten

Re: Fwd: in linux 6.3.7-200.fc38.x86_64 goes vlc in time to switch tv channels to zombie-process

[Hans Verkuil]

On 31/08/2023 13:00, Thorsten Leemhuis wrote:
> On 31.08.23 12:35, Hans Verkuil wrote:
>> On 31/08/2023 11:26, Linux regression tracking #update (Thorsten Leemhuis) wrote:
>>> [TLDR: This mail in primarily relevant for Linux kernel regression
>>> tracking. See link in footer if these mails annoy you.]
>>>
>>> On 19.06.23 02:24, Bagas Sanjaya wrote:
>>>>
>>>> I notice a regression report on Bugzilla [1]. Quoting from it:
>>>> [...]
>>>>
>>>> #regzbot introduced: v6.3.5..v6.3.7 https://bugzilla.kernel.org/show_bug.cgi?id=217566
>>>> #regzbot title: switching TV channel causes VLC and firmware loading hang
>>>
>>> #regzbot fix: 7cfab4c9dc09ca3a9d57c187894055a22bdcd
>>> #regzbot ignore-activity
>>>
>>> Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
>>> --
>>> Everything you wanna know about Linux kernel regression tracking:
>>> https://linux-regtracking.leemhuis.info/about/#tldr
>>> That page also explains what to do if mails like this annoy you.
>>
>> >From what I can gather from the bugzilla report, whatever the issue was appears
>> to be resolved or at least improved in later kernels.
> 
> I'm pretty (but not 100%) sure the initial report in that ticket were
> issues caused by a backport of a patch that was reverted later:
> https://lore.kernel.org/all/20230609082238.3671398-1-mchehab@kernel.org/

Ah, you have a better memory than I have. That might well be the culprit.
I didn't check for changes in the dvb core, I should have done that.

That patch was introduced in 6.3.7 and reverted in 6.3.9.

That doesn't quite match the "#regzbot introduced: v6.3.5..v6.3.7" report,
though. I wonder if fedora backported that problematic patch to their v6.3.5
release?

Regards,

	Hans

> 
> The versions when the problems started and some feedback in the ticket
> when things started working again (like
> https://bugzilla.kernel.org/show_bug.cgi?id=217566#c15 – 6.3.9 was when
> the revert came to 6.3.y) are strong indicators for that.
> 
> But yes, more people showed up in the ticket with problems that might or
> might not be related to the initial problem and things got confusing. I
> told them to report those problems separately. Ideally somebody would
> look into that and check if they did, yes, but I chose to ignore things
> at that point, as regression tracking is quite hard already and I have
> to draw lines somewhere. I often hate that, but otherwise I don't get
> much work done. :-/
> 
> Ciao, Thorsten

Re: Fwd: in linux 6.3.7-200.fc38.x86_64 goes vlc in time to switch tv channels to zombie-process

[Linux regression tracking (Thorsten Leemhuis)]

On 31.08.23 13:47, Hans Verkuil wrote:
> On 31/08/2023 13:00, Thorsten Leemhuis wrote:
>> On 31.08.23 12:35, Hans Verkuil wrote:
>>> On 31/08/2023 11:26, Linux regression tracking #update (Thorsten Leemhuis) wrote:
>>>> [TLDR: This mail in primarily relevant for Linux kernel regression
>>>> tracking. See link in footer if these mails annoy you.]
>>>>
>>>> On 19.06.23 02:24, Bagas Sanjaya wrote:
>>>>>
>>>>> I notice a regression report on Bugzilla [1]. Quoting from it:
>>>>> [...]
>>>>>
>>>>> #regzbot introduced: v6.3.5..v6.3.7 https://bugzilla.kernel.org/show_bug.cgi?id=217566
>>>>> #regzbot title: switching TV channel causes VLC and firmware loading hang
>>>>
>>>> #regzbot fix: 7cfab4c9dc09ca3a9d57c187894055a22bdcd
>>>> #regzbot ignore-activity
>>>>
>>>> Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
>>>> --
>>>> Everything you wanna know about Linux kernel regression tracking:
>>>> https://linux-regtracking.leemhuis.info/about/#tldr
>>>> That page also explains what to do if mails like this annoy you.
>>>
>>> >From what I can gather from the bugzilla report, whatever the issue was appears
>>> to be resolved or at least improved in later kernels.
>>
>> I'm pretty (but not 100%) sure the initial report in that ticket were
>> issues caused by a backport of a patch that was reverted later:
>> https://lore.kernel.org/all/20230609082238.3671398-1-mchehab@kernel.org/
> 
> Ah, you have a better memory than I have. That might well be the culprit.
> I didn't check for changes in the dvb core, I should have done that.
> 
> That patch was introduced in 6.3.7 and reverted in 6.3.9.
> 
> That doesn't quite match the "#regzbot introduced: v6.3.5..v6.3.7" report,
> though. I wonder if fedora backported that problematic patch to their v6.3.5
> release?

Nope, as it matches (I'd say). The reporter never bisected this and just
claimed that 6.3.5 was fine and 6.3.7 was broken (and 6.3.6 iirc was
never tested). In that case we tell regzbot that the culprit is
somewhere in that range (which is was[1]), as that's the important thing
to know in the context of the 6.3.y regression (that it also happened in
mainline is a different story).

Is this too confusing? Would it be better to handle things differently
somehow?

Ciao, Thorsten

[1] $ git rev-list v6.3.5..v6.3.7 --oneline | grep "Fix use-after-free
on race condition at dvb_frontend"
8994830135b3 media: dvb-core: Fix use-after-free on race condition at
dvb_frontend

Re: Fwd: in linux 6.3.7-200.fc38.x86_64 goes vlc in time to switch tv channels to zombie-process

[Hans Verkuil]

On 31/08/2023 14:10, Linux regression tracking (Thorsten Leemhuis) wrote:
> On 31.08.23 13:47, Hans Verkuil wrote:
>> On 31/08/2023 13:00, Thorsten Leemhuis wrote:
>>> On 31.08.23 12:35, Hans Verkuil wrote:
>>>> On 31/08/2023 11:26, Linux regression tracking #update (Thorsten Leemhuis) wrote:
>>>>> [TLDR: This mail in primarily relevant for Linux kernel regression
>>>>> tracking. See link in footer if these mails annoy you.]
>>>>>
>>>>> On 19.06.23 02:24, Bagas Sanjaya wrote:
>>>>>>
>>>>>> I notice a regression report on Bugzilla [1]. Quoting from it:
>>>>>> [...]
>>>>>>
>>>>>> #regzbot introduced: v6.3.5..v6.3.7 https://bugzilla.kernel.org/show_bug.cgi?id=217566
>>>>>> #regzbot title: switching TV channel causes VLC and firmware loading hang
>>>>>
>>>>> #regzbot fix: 7cfab4c9dc09ca3a9d57c187894055a22bdcd
>>>>> #regzbot ignore-activity
>>>>>
>>>>> Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
>>>>> --
>>>>> Everything you wanna know about Linux kernel regression tracking:
>>>>> https://linux-regtracking.leemhuis.info/about/#tldr
>>>>> That page also explains what to do if mails like this annoy you.
>>>>
>>>> >From what I can gather from the bugzilla report, whatever the issue was appears
>>>> to be resolved or at least improved in later kernels.
>>>
>>> I'm pretty (but not 100%) sure the initial report in that ticket were
>>> issues caused by a backport of a patch that was reverted later:
>>> https://lore.kernel.org/all/20230609082238.3671398-1-mchehab@kernel.org/
>>
>> Ah, you have a better memory than I have. That might well be the culprit.
>> I didn't check for changes in the dvb core, I should have done that.
>>
>> That patch was introduced in 6.3.7 and reverted in 6.3.9.
>>
>> That doesn't quite match the "#regzbot introduced: v6.3.5..v6.3.7" report,
>> though. I wonder if fedora backported that problematic patch to their v6.3.5
>> release?
> 
> Nope, as it matches (I'd say). The reporter never bisected this and just
> claimed that 6.3.5 was fine and 6.3.7 was broken (and 6.3.6 iirc was
> never tested). In that case we tell regzbot that the culprit is
> somewhere in that range (which is was[1]), as that's the important thing
> to know in the context of the 6.3.y regression (that it also happened in
> mainline is a different story).
> 
> Is this too confusing? Would it be better to handle things differently
> somehow?

Ah, I interpreted "#regzbot introduced" as "this issue was seen in these
kernels", instead of: "it was introduced in one of these kernels".

With that it matches perfectly.

Regards,

	Hans

> 
> Ciao, Thorsten
> 
> [1] $ git rev-list v6.3.5..v6.3.7 --oneline | grep "Fix use-after-free
> on race condition at dvb_frontend"
> 8994830135b3 media: dvb-core: Fix use-after-free on race condition at
> dvb_frontend