Failed to connect to 4G modem

Failed to connect to 4G modem

[JH]

Hi,

I am running kernel LTS 4.19 in an i.MX6 board with a 4G LTE modem, it
continually displayed following messages in a serial port tried and
failed to connect to LTE modem, are there any problems in kernel 4.19
LTS to support usb qmi protocol and LTE modem connection?

I did try the kernel version 5.1, it can connect to the modem, but
failed in couple of hours or days, when it disconnected, it got the
same following messages.

Are there serious problems in kernel to support usb qmi LTE modem
communication and connection?

[   43.837243] option1 ttyUSB0: GSM modem (1-port) converter now disconnected f0
[   43.882941] option 1-1:1.0: device disconnected
[   43.942788] option1 ttyUSB1: GSM modem (1-port) converter now disconnected f1
[   44.001445] option 1-1:1.2: device disconnected
[   44.011575] qmi_wwan 1-1:1.3: nonzero urb status received: -71
[   44.017461] qmi_wwan 1-1:1.3: wdm_int_callback - 0 bytes
[   44.022801] qmi_wwan 1-1:1.3: wdm_int_callback - usb_submit_urb failed with 9
[   44.059958] qmi_wwan 1-1:1.3 wwan0: unregister 'qmi_wwan' usb-ci_hdrc.1-1, We
[   47.675604] usb 1-1: new high-speed USB device number 5 using ci_hdrc
[   47.905246] usb 1-1: New USB device found, idVendor=05c6, idProduct=90b2, bc0
[   47.913732] usb 1-1: New USB device strings: Mfr=3, Product=2, SerialNumber=4
[   47.921099] usb 1-1: Product: Qualcomm CDMA Technologies MSM
[   47.927087] usb 1-1: Manufacturer: Qualcomm, Incorporated
[   47.932746] usb 1-1: SerialNumber: 5ff10299
[   47.964528] option 1-1:1.0: GSM modem (1-port) converter detected
[   47.989484] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB0
[   48.014760] option 1-1:1.2: GSM modem (1-port) converter detected
[   48.026996] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB1
[   48.048810] qmi_wwan 1-1:1.3: cdc-wdm0: USB WDM device
[   48.082751] qmi_wwan 1-1:1.3 wwan0: register 'qmi_wwan' at usb-ci_hdrc.1-1, 8
[   51.581595] usb 1-1: USB disconnect, device number 5
[   51.613737] option1 ttyUSB0: GSM modem (1-port) converter now disconnected f0
[   51.644564] option 1-1:1.0: device disconnected
[   51.713919] option1 ttyUSB1: GSM modem (1-port) converter now disconnected f1
[   51.771139] option 1-1:1.2: device disconnected

Thank you.

Kind regards,

- jh

Re: Failed to connect to 4G modem

[Greg KH]

On Tue, Sep 17, 2019 at 09:29:34PM +1000, JH wrote:
> Hi,
> 
> I am running kernel LTS 4.19 in an i.MX6 board with a 4G LTE modem, it
> continually displayed following messages in a serial port tried and
> failed to connect to LTE modem, are there any problems in kernel 4.19
> LTS to support usb qmi protocol and LTE modem connection?
> 
> I did try the kernel version 5.1, it can connect to the modem, but
> failed in couple of hours or days, when it disconnected, it got the
> same following messages.
> 
> Are there serious problems in kernel to support usb qmi LTE modem
> communication and connection?
> 
> [   43.837243] option1 ttyUSB0: GSM modem (1-port) converter now disconnected f0
> [   43.882941] option 1-1:1.0: device disconnected
> [   43.942788] option1 ttyUSB1: GSM modem (1-port) converter now disconnected f1
> [   44.001445] option 1-1:1.2: device disconnected
> [   44.011575] qmi_wwan 1-1:1.3: nonzero urb status received: -71
> [   44.017461] qmi_wwan 1-1:1.3: wdm_int_callback - 0 bytes
> [   44.022801] qmi_wwan 1-1:1.3: wdm_int_callback - usb_submit_urb failed with 9
> [   44.059958] qmi_wwan 1-1:1.3 wwan0: unregister 'qmi_wwan' usb-ci_hdrc.1-1, We
> [   47.675604] usb 1-1: new high-speed USB device number 5 using ci_hdrc
> [   47.905246] usb 1-1: New USB device found, idVendor=05c6, idProduct=90b2, bc0
> [   47.913732] usb 1-1: New USB device strings: Mfr=3, Product=2, SerialNumber=4
> [   47.921099] usb 1-1: Product: Qualcomm CDMA Technologies MSM
> [   47.927087] usb 1-1: Manufacturer: Qualcomm, Incorporated
> [   47.932746] usb 1-1: SerialNumber: 5ff10299
> [   47.964528] option 1-1:1.0: GSM modem (1-port) converter detected
> [   47.989484] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB0
> [   48.014760] option 1-1:1.2: GSM modem (1-port) converter detected
> [   48.026996] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB1
> [   48.048810] qmi_wwan 1-1:1.3: cdc-wdm0: USB WDM device
> [   48.082751] qmi_wwan 1-1:1.3 wwan0: register 'qmi_wwan' at usb-ci_hdrc.1-1, 8
> [   51.581595] usb 1-1: USB disconnect, device number 5
> [   51.613737] option1 ttyUSB0: GSM modem (1-port) converter now disconnected f0
> [   51.644564] option 1-1:1.0: device disconnected
> [   51.713919] option1 ttyUSB1: GSM modem (1-port) converter now disconnected f1
> [   51.771139] option 1-1:1.2: device disconnected

The device is disconnecting itself from the USB bus, and then connecting
itself, and then disconnecting...

Probably an electrical issue, the kernel can not disconnect a device
directly from the USB bus, that information comes from the USB hub
itself.

Try your connections.

thanks,

greg k-h

Re: Failed to connect to 4G modem

[JH]

Hi Greg,

On 9/17/19, Greg KH <gregkh@linuxfoundation.org> wrote:
> On Tue, Sep 17, 2019 at 09:29:34PM +1000, JH wrote:
>> Hi,
>>
>> I am running kernel LTS 4.19 in an i.MX6 board with a 4G LTE modem, it
>> continually displayed following messages in a serial port tried and
>> failed to connect to LTE modem, are there any problems in kernel 4.19
>> LTS to support usb qmi protocol and LTE modem connection?
>>
>> I did try the kernel version 5.1, it can connect to the modem, but
>> failed in couple of hours or days, when it disconnected, it got the
>> same following messages.
>>
>> Are there serious problems in kernel to support usb qmi LTE modem
>> communication and connection?
>>
>> [   43.837243] option1 ttyUSB0: GSM modem (1-port) converter now
>> disconnected f0
>> [   43.882941] option 1-1:1.0: device disconnected
>> [   43.942788] option1 ttyUSB1: GSM modem (1-port) converter now
>> disconnected f1
>> [   44.001445] option 1-1:1.2: device disconnected
>> [   44.011575] qmi_wwan 1-1:1.3: nonzero urb status received: -71
>> [   44.017461] qmi_wwan 1-1:1.3: wdm_int_callback - 0 bytes
>> [   44.022801] qmi_wwan 1-1:1.3: wdm_int_callback - usb_submit_urb failed
>> with 9
>> [   44.059958] qmi_wwan 1-1:1.3 wwan0: unregister 'qmi_wwan'
>> usb-ci_hdrc.1-1, We
>> [   47.675604] usb 1-1: new high-speed USB device number 5 using ci_hdrc
>> [   47.905246] usb 1-1: New USB device found, idVendor=05c6,
>> idProduct=90b2, bc0
>> [   47.913732] usb 1-1: New USB device strings: Mfr=3, Product=2,
>> SerialNumber=4
>> [   47.921099] usb 1-1: Product: Qualcomm CDMA Technologies MSM
>> [   47.927087] usb 1-1: Manufacturer: Qualcomm, Incorporated
>> [   47.932746] usb 1-1: SerialNumber: 5ff10299
>> [   47.964528] option 1-1:1.0: GSM modem (1-port) converter detected
>> [   47.989484] usb 1-1: GSM modem (1-port) converter now attached to
>> ttyUSB0
>> [   48.014760] option 1-1:1.2: GSM modem (1-port) converter detected
>> [   48.026996] usb 1-1: GSM modem (1-port) converter now attached to
>> ttyUSB1
>> [   48.048810] qmi_wwan 1-1:1.3: cdc-wdm0: USB WDM device
>> [   48.082751] qmi_wwan 1-1:1.3 wwan0: register 'qmi_wwan' at
>> usb-ci_hdrc.1-1, 8
>> [   51.581595] usb 1-1: USB disconnect, device number 5
>> [   51.613737] option1 ttyUSB0: GSM modem (1-port) converter now
>> disconnected f0
>> [   51.644564] option 1-1:1.0: device disconnected
>> [   51.713919] option1 ttyUSB1: GSM modem (1-port) converter now
>> disconnected f1
>> [   51.771139] option 1-1:1.2: device disconnected
>
> The device is disconnecting itself from the USB bus, and then connecting
> itself, and then disconnecting...
>
> Probably an electrical issue, the kernel can not disconnect a device
> directly from the USB bus, that information comes from the USB hub
> itself.

That was always my thought until I tried kernel 5.1 under the same
platform (nothing changed except the kernel version), the kernel 5.1
can connect to the 4G modem, I could not tell the hardware engineer if
it was hardware problem where kernel 5.1 can connect, kernel 4.19
could not, how would you explain it? Seems some differences between
kernel 5.1 and kernel 4.19, what I could be missing?

I cannot use kernel 5, we need kernel LTS on product, too late to wait
for 5.4 LTS.

Thanks Greg.

- jh

Re: Failed to connect to 4G modem

[Lars Melin]

On 9/18/2019 04:38, JH wrote:
......
> 
> That was always my thought until I tried kernel 5.1 under the same
> platform (nothing changed except the kernel version), the kernel 5.1
> can connect to the 4G modem, I could not tell the hardware engineer if
> it was hardware problem where kernel 5.1 can connect, kernel 4.19
> could not, how would you explain it? Seems some differences between
> kernel 5.1 and kernel 4.19, what I could be missing?

Tell your hardware engineer to log the VBUS supply together with the 
current consumption of the 4G card.
A glitch in the VBUS supply, often caused by an increase in current 
consumption is a common reason for a usb modem to reset and temporarily 
fall off the usb bus.

br
Lars

Re: Failed to connect to 4G modem

[Greg KH]

On Wed, Sep 18, 2019 at 07:38:14AM +1000, JH wrote:
> Hi Greg,
> 
> On 9/17/19, Greg KH <gregkh@linuxfoundation.org> wrote:
> > On Tue, Sep 17, 2019 at 09:29:34PM +1000, JH wrote:
> >> Hi,
> >>
> >> I am running kernel LTS 4.19 in an i.MX6 board with a 4G LTE modem, it
> >> continually displayed following messages in a serial port tried and
> >> failed to connect to LTE modem, are there any problems in kernel 4.19
> >> LTS to support usb qmi protocol and LTE modem connection?
> >>
> >> I did try the kernel version 5.1, it can connect to the modem, but
> >> failed in couple of hours or days, when it disconnected, it got the
> >> same following messages.
> >>
> >> Are there serious problems in kernel to support usb qmi LTE modem
> >> communication and connection?
> >>
> >> [   43.837243] option1 ttyUSB0: GSM modem (1-port) converter now
> >> disconnected f0
> >> [   43.882941] option 1-1:1.0: device disconnected
> >> [   43.942788] option1 ttyUSB1: GSM modem (1-port) converter now
> >> disconnected f1
> >> [   44.001445] option 1-1:1.2: device disconnected
> >> [   44.011575] qmi_wwan 1-1:1.3: nonzero urb status received: -71
> >> [   44.017461] qmi_wwan 1-1:1.3: wdm_int_callback - 0 bytes
> >> [   44.022801] qmi_wwan 1-1:1.3: wdm_int_callback - usb_submit_urb failed
> >> with 9
> >> [   44.059958] qmi_wwan 1-1:1.3 wwan0: unregister 'qmi_wwan'
> >> usb-ci_hdrc.1-1, We
> >> [   47.675604] usb 1-1: new high-speed USB device number 5 using ci_hdrc
> >> [   47.905246] usb 1-1: New USB device found, idVendor=05c6,
> >> idProduct=90b2, bc0
> >> [   47.913732] usb 1-1: New USB device strings: Mfr=3, Product=2,
> >> SerialNumber=4
> >> [   47.921099] usb 1-1: Product: Qualcomm CDMA Technologies MSM
> >> [   47.927087] usb 1-1: Manufacturer: Qualcomm, Incorporated
> >> [   47.932746] usb 1-1: SerialNumber: 5ff10299
> >> [   47.964528] option 1-1:1.0: GSM modem (1-port) converter detected
> >> [   47.989484] usb 1-1: GSM modem (1-port) converter now attached to
> >> ttyUSB0
> >> [   48.014760] option 1-1:1.2: GSM modem (1-port) converter detected
> >> [   48.026996] usb 1-1: GSM modem (1-port) converter now attached to
> >> ttyUSB1
> >> [   48.048810] qmi_wwan 1-1:1.3: cdc-wdm0: USB WDM device
> >> [   48.082751] qmi_wwan 1-1:1.3 wwan0: register 'qmi_wwan' at
> >> usb-ci_hdrc.1-1, 8
> >> [   51.581595] usb 1-1: USB disconnect, device number 5
> >> [   51.613737] option1 ttyUSB0: GSM modem (1-port) converter now
> >> disconnected f0
> >> [   51.644564] option 1-1:1.0: device disconnected
> >> [   51.713919] option1 ttyUSB1: GSM modem (1-port) converter now
> >> disconnected f1
> >> [   51.771139] option 1-1:1.2: device disconnected
> >
> > The device is disconnecting itself from the USB bus, and then connecting
> > itself, and then disconnecting...
> >
> > Probably an electrical issue, the kernel can not disconnect a device
> > directly from the USB bus, that information comes from the USB hub
> > itself.
> 
> That was always my thought until I tried kernel 5.1 under the same
> platform (nothing changed except the kernel version), the kernel 5.1
> can connect to the 4G modem, I could not tell the hardware engineer if
> it was hardware problem where kernel 5.1 can connect, kernel 4.19
> could not, how would you explain it? Seems some differences between
> kernel 5.1 and kernel 4.19, what I could be missing?
> 
> I cannot use kernel 5, we need kernel LTS on product, too late to wait
> for 5.4 LTS.

Can you use 'git bisect' to find the commit that fixes the issue?  That
way we can backport it to the 4.19.y tree for you.

Otherwise, just use 5.3 now and then 5.4 when it comes out in a few
months.

good luck!

greg k-h

Re: Failed to connect to 4G modem

[Bjørn Mork]

Greg KH <gregkh@linuxfoundation.org> writes:

>> >> [   44.059958] qmi_wwan 1-1:1.3 wwan0: unregister 'qmi_wwan' usb-ci_hdrc.1-1, We
..
>> That was always my thought until I tried kernel 5.1 under the same
>> platform (nothing changed except the kernel version), the kernel 5.1
>> can connect to the 4G modem, I could not tell the hardware engineer if
>> it was hardware problem where kernel 5.1 can connect, kernel 4.19
>> could not, how would you explain it? Seems some differences between
>> kernel 5.1 and kernel 4.19, what I could be missing?
>> 
>> I cannot use kernel 5, we need kernel LTS on product, too late to wait
>> for 5.4 LTS.
>
> Can you use 'git bisect' to find the commit that fixes the issue?  That
> way we can backport it to the 4.19.y tree for you.

Yes, please.

But if I were to guess based on the above info, then I'd start looking
at the chipidea changes. Commit 2c4593ecc920 ("usb: chipidea: host:
override ehci->hub_control") looks particularily interesting.


Bjørn

Re: Failed to connect to 4G modem

[JH]

On 9/19/19, Bjørn Mork <bjorn@mork.no> wrote:
> Greg KH <gregkh@linuxfoundation.org> writes:
>
>>> >> [   44.059958] qmi_wwan 1-1:1.3 wwan0: unregister 'qmi_wwan'
>>> >> usb-ci_hdrc.1-1, We
> ..
>>> That was always my thought until I tried kernel 5.1 under the same
>>> platform (nothing changed except the kernel version), the kernel 5.1
>>> can connect to the 4G modem, I could not tell the hardware engineer if
>>> it was hardware problem where kernel 5.1 can connect, kernel 4.19
>>> could not, how would you explain it? Seems some differences between
>>> kernel 5.1 and kernel 4.19, what I could be missing?
>>>
>>> I cannot use kernel 5, we need kernel LTS on product, too late to wait
>>> for 5.4 LTS.
>>
>> Can you use 'git bisect' to find the commit that fixes the issue?  That
>> way we can backport it to the 4.19.y tree for you.

Is that the fix?

commit 7c8e8909417eb6342ac487dc5ab3076d46718f71
Author: Peter Chen <peter.chen@nxp.com>
Date:   Tue Oct 16 09:17:02 2018 +0800

    usb: chipidea: imx: add HSIC support

Fixes: 7c8e8909417e ("usb: chipidea: imx: add HSIC support")

> Yes, please.
>
> But if I were to guess based on the above info, then I'd start looking
> at the chipidea changes. Commit 2c4593ecc920 ("usb: chipidea: host:
> override ehci->hub_control") looks particularily interesting.

Don't bother to backport it to the 4.19.y, I can use 5.3, and wait for 5.4.

Thank you all.

- jupiter

Re: Failed to connect to 4G modem

[JH]

Hi Greg,

On 9/18/19, Greg KH <gregkh@linuxfoundation.org> wrote:
> Otherwise, just use 5.3 now and then 5.4 when it comes out in a few
> months.

My apology for an off topic question. I discussed with my colleague to
use 5.3, if we cannot wait for 5.4 LTS release, we will do a remote
5.4 upgrade from 5.3 on air for the product. One of my colleague
warning me that kernel 5.3 and 5.4 LTS will not be a minor upgrade, it
will be major upgrade which will have massive libraries changes. I
don't agree with it, but I could not find kernel document to state
either 5.3 and 5.4 LTS is a major or minor change. What is your
insight view? Appreciate if you could point me a reference to prove my
colleague is wrong.

Thank you very much, apologize again.

Kind regards,

- jupiter

> good luck!
>
> greg k-h
>

Re: Failed to connect to 4G modem

[Greg KH]

On Sat, Sep 21, 2019 at 08:10:30AM +1000, JH wrote:
> Hi Greg,
> 
> On 9/18/19, Greg KH <gregkh@linuxfoundation.org> wrote:
> > Otherwise, just use 5.3 now and then 5.4 when it comes out in a few
> > months.
> 
> My apology for an off topic question. I discussed with my colleague to
> use 5.3, if we cannot wait for 5.4 LTS release, we will do a remote
> 5.4 upgrade from 5.3 on air for the product. One of my colleague
> warning me that kernel 5.3 and 5.4 LTS will not be a minor upgrade, it
> will be major upgrade which will have massive libraries changes. I
> don't agree with it, but I could not find kernel document to state
> either 5.3 and 5.4 LTS is a major or minor change. What is your
> insight view? Appreciate if you could point me a reference to prove my
> colleague is wrong.

You should never have to update any userspace code or library if the
kernel is updated as we guarantee backwards compatibility.  If we did
break something, please let us know and we will work very hard to fix
it.

This is a guarantee we made back in 2007 or so, and have been sticking
to it since.

There is no "major" upgrade issue here, the kernel does a new release
every 3 months and changes the number, showing it is "newer" than the
previous one.

Hope this helps,

greg k-h

Re: Failed to connect to 4G modem

[JH]

Hi Greg,

On 9/21/19, Greg KH <gregkh@linuxfoundation.org> wrote:
> You should never have to update any userspace code or library if the
> kernel is updated as we guarantee backwards compatibility.  If we did
> break something, please let us know and we will work very hard to fix
> it.
>
> This is a guarantee we made back in 2007 or so, and have been sticking
> to it since.
>
> There is no "major" upgrade issue here, the kernel does a new release
> every 3 months and changes the number, showing it is "newer" than the
> previous one.
>
> Hope this helps,

That demystified the kernel version many people misinterpreted, so I
can tell my colleagues we are ensured there would be no libraries
changes upgrading 5.3 to 5.4 LTS.

Thank you so much.

Kind regards,

- jupiter

> greg k-h
>