Problem with 40Mhz on 2.5GHz with Intel 8260

Problem with 40Mhz on 2.5GHz with Intel 8260

[Volker Mische]

Hi,

I'm having connectivity issues with an Intel 8260 on a 2.5GHz network
when using 40Mhz. I'm getting errors like

    Queue 2 stuck for 10000 ms.

I've upgrade my system to the firmware version 21 (21.373438.0) and
Kernel 4.8.0-rc6 in hope that it fixes the issue and to be able to debug
the problem.

I then found the page about platform noise [1]. I don't have any issue
for several hours now (normally I was hitting the issue every few
minutes) as I've set the cfg80211_disable_40mhz_24ghz parameter.

Now I wonder, is it worth debugging the issue with being on 40MHz or is
disabling the proper solution and I should bother.

[1]:
https://wireless.wiki.kernel.org/en/users/drivers/iwlwifi#about_platform_noise

Cheers,
  Volker

Re: Problem with 40Mhz on 2.5GHz with Intel 8260

[Emmanuel Grumbach]

Hi,

On Mon, Sep 19, 2016 at 5:00 PM, Volker Mische <volker.mische@gmail.com> wrote:
> Hi,
>
> I'm having connectivity issues with an Intel 8260 on a 2.5GHz network
> when using 40Mhz. I'm getting errors like
>
>     Queue 2 stuck for 10000 ms.
>
> I've upgrade my system to the firmware version 21 (21.373438.0) and
> Kernel 4.8.0-rc6 in hope that it fixes the issue and to be able to debug
> the problem.
>
> I then found the page about platform noise [1]. I don't have any issue
> for several hours now (normally I was hitting the issue every few
> minutes) as I've set the cfg80211_disable_40mhz_24ghz parameter.
>
> Now I wonder, is it worth debugging the issue with being on 40MHz or is
> disabling the proper solution and I should bother.

Well... depends whom you ask and how much time you have :)
We tried a few times to debug those, but they take a very long time to debug
since typically we need lots of reproductions and the firmware team
doesn't always
the time to look at the data immediately so in the end, the people who
reported this
originally went away.
Note that 40MHz on 2.4GHz is not an optimal configuration in crowded
environment,
but if you live in a place where you are pretty much the only one using those
frequencies, then, it can be beneficial.
What you can try is to disable low power states (by using power_scheme
in iwlmvm)
and see if it helps. This setting has a bigger impact than
cfg80211_disable_40mhz_24ghz
but it can give a hint as where the problem is coming from.

>
> [1]:
> https://wireless.wiki.kernel.org/en/users/drivers/iwlwifi#about_platform_noise
>
> Cheers,
>   Volker

Re: Problem with 40Mhz on 2.5GHz with Intel 8260

[Volker Mische]

Hi,

On 09/20/2016 07:39 AM, Emmanuel Grumbach wrote:
> On Mon, Sep 19, 2016 at 5:00 PM, Volker Mische <volker.mische@gmail.com> wrote:
>> I'm having connectivity issues with an Intel 8260 on a 2.5GHz network
>> when using 40Mhz. I'm getting errors like
>>
>>     Queue 2 stuck for 10000 ms.
>>
>> I've upgrade my system to the firmware version 21 (21.373438.0) and
>> Kernel 4.8.0-rc6 in hope that it fixes the issue and to be able to debug
>> the problem.
>>
>> I then found the page about platform noise [1]. I don't have any issue
>> for several hours now (normally I was hitting the issue every few
>> minutes) as I've set the cfg80211_disable_40mhz_24ghz parameter.
>>
>> Now I wonder, is it worth debugging the issue with being on 40MHz or is
>> disabling the proper solution and I should bother.
> 
> Well... depends whom you ask and how much time you have :)

I really want to get this sorted out.


> We tried a few times to debug those, but they take a very long time to debug
> since typically we need lots of reproductions and the firmware team
> doesn't always
> the time to look at the data immediately so in the end, the people who
> reported this
> originally went away.
> Note that 40MHz on 2.4GHz is not an optimal configuration in crowded
> environment,
> but if you live in a place where you are pretty much the only one using those
> frequencies, then, it can be beneficial.

It's at home. I normally see only one other wifi (I need to check which
frequency that one is using).


> What you can try is to disable low power states (by using power_scheme
> in iwlmvm) and see if it helps.

I will try that.

> This setting has a bigger impact than cfg80211_disable_40mhz_24ghz
> but it can give a hint as where the problem is coming from.

I'll report back.

Should I open a bug report (or use an existing one) or should we keep
the discussion on the mailing list?


Cheers,
  Volker


>> [1]:
>> https://wireless.wiki.kernel.org/en/users/drivers/iwlwifi#about_platform_noise

Re: Problem with 40Mhz on 2.5GHz with Intel 8260

[Volker Mische]

Hi,

On 09/20/2016 08:22 AM, Volker Mische wrote:
> On 09/20/2016 07:39 AM, Emmanuel Grumbach wrote:
>> On Mon, Sep 19, 2016 at 5:00 PM, Volker Mische <volker.mische@gmail.com> wrote:
>>> I'm having connectivity issues with an Intel 8260 on a 2.5GHz network
>>> when using 40Mhz. I'm getting errors like
>>>
>>>     Queue 2 stuck for 10000 ms.
>>>
>>> I've upgrade my system to the firmware version 21 (21.373438.0) and
>>> Kernel 4.8.0-rc6 in hope that it fixes the issue and to be able to debug
>>> the problem.
>>>
>>> I then found the page about platform noise [1]. I don't have any issue
>>> for several hours now (normally I was hitting the issue every few
>>> minutes) as I've set the cfg80211_disable_40mhz_24ghz parameter.

>> We tried a few times to debug those, but they take a very long time to debug
>> since typically we need lots of reproductions and the firmware team
>> doesn't always
>> the time to look at the data immediately so in the end, the people who
>> reported this
>> originally went away.
>> Note that 40MHz on 2.4GHz is not an optimal configuration in crowded
>> environment,
>> but if you live in a place where you are pretty much the only one using those
>> frequencies, then, it can be beneficial.
> 
> It's at home. I normally see only one other wifi (I need to check which
> frequency that one is using).
> 
> 
>> What you can try is to disable low power states (by using power_scheme
>> in iwlmvm) and see if it helps.
> 
> I will try that.

I've set the iwlmvm power_scheme to 1 (and allowed the 40Mhz
connection). First I thought it's good, but after a while the queue
still got stuck. Especially after waking up from a suspend (not sure if
that matters).

What are the next steps?

>>> [1]:
>>> https://wireless.wiki.kernel.org/en/users/drivers/iwlwifi#about_platform_noise

Cheers,
  Volker

Re: Problem with 40Mhz on 2.5GHz with Intel 8260

[Emmanuel Grumbach]

> Hi,
>
> On 09/20/2016 08:22 AM, Volker Mische wrote:
>> On 09/20/2016 07:39 AM, Emmanuel Grumbach wrote:
>>> On Mon, Sep 19, 2016 at 5:00 PM, Volker Mische <volker.mische@gmail.com> wrote:
>>>> I'm having connectivity issues with an Intel 8260 on a 2.5GHz network
>>>> when using 40Mhz. I'm getting errors like
>>>>
>>>>     Queue 2 stuck for 10000 ms.
>>>>
>>>> I've upgrade my system to the firmware version 21 (21.373438.0) and
>>>> Kernel 4.8.0-rc6 in hope that it fixes the issue and to be able to debug
>>>> the problem.
>>>>
>>>> I then found the page about platform noise [1]. I don't have any issue
>>>> for several hours now (normally I was hitting the issue every few
>>>> minutes) as I've set the cfg80211_disable_40mhz_24ghz parameter.
>
>>> We tried a few times to debug those, but they take a very long time to debug
>>> since typically we need lots of reproductions and the firmware team
>>> doesn't always
>>> the time to look at the data immediately so in the end, the people who
>>> reported this
>>> originally went away.
>>> Note that 40MHz on 2.4GHz is not an optimal configuration in crowded
>>> environment,
>>> but if you live in a place where you are pretty much the only one using those
>>> frequencies, then, it can be beneficial.
>>
>> It's at home. I normally see only one other wifi (I need to check which
>> frequency that one is using).
>>
>>
>>> What you can try is to disable low power states (by using power_scheme
>>> in iwlmvm) and see if it helps.
>>
>> I will try that.
>
> I've set the iwlmvm power_scheme to 1 (and allowed the 40Mhz
> connection). First I thought it's good, but after a while the queue
> still got stuck. Especially after waking up from a suspend (not sure if
> that matters).

Ok - good to know.

>
> What are the next steps?

can you try to unplug the power cord? I had reports that said that
this can help. Again, just a debug step to give us a hint of what you
can be experiencing.
Besides this, we need to go for firmware debugging. But as I said,
don't expect this to be fast and easy. Please open a bug in
bugzilla.kernel.org. CC linuxwifi@intel.com and we will guide you
there on how to provide the information we need.

Re: Problem with 40Mhz on 2.5GHz with Intel 8260

[Volker Mische]

Hi,

On 09/21/2016 08:54 AM, Emmanuel Grumbach wrote:
>> On 09/20/2016 08:22 AM, Volker Mische wrote:
>>> On 09/20/2016 07:39 AM, Emmanuel Grumbach wrote:
>>>> On Mon, Sep 19, 2016 at 5:00 PM, Volker Mische <volker.mische@gmail.com> wrote:
>>>>> I'm having connectivity issues with an Intel 8260 on a 2.5GHz network
>>>>> when using 40Mhz. I'm getting errors like
>>>>>
>>>>>     Queue 2 stuck for 10000 ms.
>>>>>
>>>>> I've upgrade my system to the firmware version 21 (21.373438.0) and
>>>>> Kernel 4.8.0-rc6 in hope that it fixes the issue and to be able to debug
>>>>> the problem.
>>>>>
>>>>> I then found the page about platform noise [1]. I don't have any issue
>>>>> for several hours now (normally I was hitting the issue every few
>>>>> minutes) as I've set the cfg80211_disable_40mhz_24ghz parameter.
>>
>>>> We tried a few times to debug those, but they take a very long time to debug
>>>> since typically we need lots of reproductions and the firmware team
>>>> doesn't always
>>>> the time to look at the data immediately so in the end, the people who
>>>> reported this
>>>> originally went away.
>>>> Note that 40MHz on 2.4GHz is not an optimal configuration in crowded
>>>> environment,
>>>> but if you live in a place where you are pretty much the only one using those
>>>> frequencies, then, it can be beneficial.
>>>
>>> It's at home. I normally see only one other wifi (I need to check which
>>> frequency that one is using).
>>>
>>>
>>>> What you can try is to disable low power states (by using power_scheme
>>>> in iwlmvm) and see if it helps.
>>>
>>> I will try that.
>>
>> I've set the iwlmvm power_scheme to 1 (and allowed the 40Mhz
>> connection). First I thought it's good, but after a while the queue
>> still got stuck. Especially after waking up from a suspend (not sure if
>> that matters).
> 
> Ok - good to know.
> 
>>
>> What are the next steps?
> 
> can you try to unplug the power cord? I had reports that said that
> this can help. Again, just a debug step to give us a hint of what you
> can be experiencing.

Unplug without any module parameters or combined with the
cfg80211_disable_40mhz_24ghz or power_scheme one?


> Besides this, we need to go for firmware debugging. But as I said,
> don't expect this to be fast and easy. Please open a bug in
> bugzilla.kernel.org. CC linuxwifi@intel.com and we will guide you
> there on how to provide the information we need.

OK, will do once I did try with unplugging. I've seen previous reports
on the issue. As I'm already running a Kernel compiled from source I
hope that at least I can move fast :)

Cheers,
  Volker

Re: Problem with 40Mhz on 2.5GHz with Intel 8260

[Emmanuel Grumbach]

>>>
>>> I've set the iwlmvm power_scheme to 1 (and allowed the 40Mhz
>>> connection). First I thought it's good, but after a while the queue
>>> still got stuck. Especially after waking up from a suspend (not sure if
>>> that matters).
>>
>> Ok - good to know.
>>
>>>
>>> What are the next steps?
>>
>> can you try to unplug the power cord? I had reports that said that
>> this can help. Again, just a debug step to give us a hint of what you
>> can be experiencing.
>
> Unplug without any module parameters or combined with the
> cfg80211_disable_40mhz_24ghz or power_scheme one?

Nope - default configuration.

>
>
>> Besides this, we need to go for firmware debugging. But as I said,
>> don't expect this to be fast and easy. Please open a bug in
>> bugzilla.kernel.org. CC linuxwifi@intel.com and we will guide you
>> there on how to provide the information we need.
>
> OK, will do once I did try with unplugging. I've seen previous reports
> on the issue. As I'm already running a Kernel compiled from source I
> hope that at least I can move fast :)

Oh - the firmware debugging doesn't involve any source modification.

>
> Cheers,
>   Volker
>

Re: Problem with 40Mhz on 2.5GHz with Intel 8260

[Volker Mische]

Hi,

On 09/21/2016 09:20 AM, Emmanuel Grumbach wrote:
>>> can you try to unplug the power cord? I had reports that said that
>>> this can help. Again, just a debug step to give us a hint of what you
>>> can be experiencing.
>>
>> Unplug without any module parameters or combined with the
>> cfg80211_disable_40mhz_24ghz or power_scheme one?
> 
> Nope - default configuration.

the issue also happens when the power cord is unplugged.

>>> Besides this, we need to go for firmware debugging. But as I said,
>>> don't expect this to be fast and easy. Please open a bug in
>>> bugzilla.kernel.org. CC linuxwifi@intel.com and we will guide you
>>> there on how to provide the information we need.

I've filled bug 172431

[1]: https://bugzilla.kernel.org/show_bug.cgi?id=172431

Cheers,
  Volker

Re: Problem with 40Mhz on 2.5GHz with Intel 8260

[Emmanuel Grumbach]

On Wed, Sep 21, 2016 at 11:19 PM, Volker Mische <volker.mische@gmail.com> wrote:
> Hi,
>
> On 09/21/2016 09:20 AM, Emmanuel Grumbach wrote:
>>>> can you try to unplug the power cord? I had reports that said that
>>>> this can help. Again, just a debug step to give us a hint of what you
>>>> can be experiencing.
>>>
>>> Unplug without any module parameters or combined with the
>>> cfg80211_disable_40mhz_24ghz or power_scheme one?
>>
>> Nope - default configuration.
>
> the issue also happens when the power cord is unplugged.

Ok - thanks for trying.

>
>>>> Besides this, we need to go for firmware debugging. But as I said,
>>>> don't expect this to be fast and easy. Please open a bug in
>>>> bugzilla.kernel.org. CC linuxwifi@intel.com and we will guide you
>>>> there on how to provide the information we need.
>
> I've filled bug 172431
>
> [1]: https://bugzilla.kernel.org/show_bug.cgi?id=172431

Saw that. Thanks.

>
> Cheers,
>   Volker