[Letux-kernel] Modem disappears GTA04A4

[H. Nikolaus Schaller]

> Am 26.01.2019 um 15:22 schrieb Andreas Kemnade <andreas at kemnade.info>:
> 
> Hi,
> 
> On Sat, 26 Jan 2019 14:35:48 +0100
> Jake <jake42 at rommelwood.de> wrote:
> 
>> On Fri, 2019-01-25 at 07:04 +0100, Andreas Kemnade wrote:
>>> On Sun, 20 Jan 2019 21:29:39 +0100
>>> Andreas Kemnade <andreas at kemnade.info> wrote:
>>> 
>>>> On Sun, 13 Jan 2019 23:28:35 +0100
>>>> Jake <jake42 at rommelwood.de> wrote:
>>>> 
>>>>> Hi,
>>>>> 
>>>>> I'm experiencing a problem with the modem disappearing on GTA04.
>>>>> For example when writing text messages to and fro with suspends
>>>>> in
>>>>> between it happens at times, that the modem /dev/ttyHS* files
>>>>> disappear. The modem is still unblocked in rfkill. 
>>>>> 
>>>>> I don't have any logs yet. I usually powered off the GTA04A4,
>>>>> removed
>>>>> the battery for a few seconds, reinserted and booted again to
>>>>> continue
>>>>> the conversation as soon as possible.
>>>>> 
>>>>> How can I toggle the gpio 186? to reenable the modem manually?
>>>>> 
>>>>> My observations so far:
>>>>> 4.19-rc7: modem disappears sporadically
>>>>> 4.19.12: modem disappears sporadically
>>>>> 4.20: does not wake on incoming call/text    
>>>> 
>>>> can reproduce this. The corresponding event device works, but
>>>> wakeup 
>>>> does not work. Ruled out: dtb changes. Will do further research.
>>>> 
>>> 
>>> does
>>> devmem2 0x48002A1A h 0x4104
>>> 
>>> help also for you? Just execute it after every boot. For me it helps
>>> with 4.20,
>>> but no idea why it is needed now.  
>> it helps. tested on 4.20.2.
> 
> ok, then I will prepare a patch for upstreaming. It will also fix
> wakeup by aux button. I guess, we do not need the wwan-wakeup-button,
> just a wakeup somehow.

I think it can be useful if the wakeup source is reported to a GUI in that case.
That is why we have a button which could automatically open some phone
application.

BR,
Nikolaus