On 9/19/19, Bjørn Mork <bjorn@xxxxxxx> wrote:
> Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> 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@xxxxxxx>
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
