[Gta04-owner] Replicant modem suspend behavior

[Lukas Maerdian]

Am 12.12.2014 um 22:02 schrieb Sebastian Krzyszkowiak:
> On Fri, Dec 12, 2014 at 6:11 PM, Lukas Maerdian <luk at slyon.de> wrote:
>> Am 12.12.2014 um 16:41 schrieb Rico Rommel:
>>> Am Freitag, 12. Dezember 2014, 16:17:54 schrieb Lukas Maerdian:
>>>> Hello everybody,
>>>>
>>>> since quite some time I'm trying to debug the Replicant modem suspend
>>>> behavior, but I cannot find any solution...
>>>>
>>>> My problem is that the modem transitions into a strange state after a
>>>> suspend/resume cycle, where it just returns the CME error 0 (phone
>>>> failure) to every single AT command I send. If I kill/restart the Radio
>>>> Interface Layer ("killall rild"), the modem seems to be working fine
>>>> again, so I guess a "AT+CFUN=0; AT+CFUN=1" correctly resets the modem.
>>>
>>> I don't know if it's related to this or a bug in my phonesoftware, but on
>>> resume my phone switches automatically to airplane mode. So I have to set
>>> operating mode everytime the phone resumes.
>>> I use kernel 3.12 and can't remember, if this problem also existed with kernel
>>> 3.7.
>>
>> Hi Rico,
>>
>> indeed this seems to be the case! I'm on 3.12 as well and directly after
>> resume everything is fine (CFUN: 1) but about 1 sec after the resume I
>> receive a "+CREG: 0" URC and if I issue "AT+CFUN?" afterwards I receive
>> a "+CFUN: 4", i.e. airplane mode.
>>
>> So, after this I can simply switch airplane mode off (AT+CFUN=1) and the
>> device will be back online! Well... the 3G connection still needs to be
>> re-configured, but this is another issue.
>>
>> Thanks a bunch, this was the missing piece I was looking for!
>>
>> I assume the modem is still operational during suspend, i.e. is able to
>> receive calls/SMS and interrupt the CPU, can you confirm this?
>>
>> Best,
>>   Lukas
> 
> Gee, I tried to debug it a few times, but always thought it was some
> FSO issue - so no wonder that I failed. Never even thought that it
> could be on lower layer!
> 
> That explains a lot. Now let's find out why it happens at all :)

Right! Probably something changed in the hso.c driver between Linux
v3.7..v3.12 and we have to spot it!

Best,
  Lukas

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 473 bytes
Desc: OpenPGP digital signature
URL: <http://lists.goldelico.com/pipermail/gta04-owner/attachments/20141213/03972d87/attachment.asc>