[om2008.8] Testing packages for Qtopia

[Michael Shiloh]

Holger Freyther wrote:
> Hey,
> 
> I think that the No PIN Dialog (#1765, #1798), GSM Antenna/No Network (#1766),  
> missing SMS notification (#1792) and the various duplicates and variations 
> (no phonebook..) are related to a funny issue in the QAtChat and TI Calypso 
> handling.
> 
> As the planned "testing feed" might need one more day and the issue is 
> obviously quite big I have created a small Qtopia update.
> 
> You can add: "src/gz zecke http://people.openmoko.org/zecke/qtopia-testing/" 
> to your feed config and do a opkg update, opkg upgrade to get the Qtopia 
> fixes. Feedback is welcomed.
> 
> 
> 
> Explanation of the issue:
> 
> Players:
> 	- QAtChat is responsible for queueing commands and forwarding responses
> 	- TI Calypso is the hardware/module that runs the GSM firmware.
> 
> Ti Calypso:
> 	- The module does PM on it's own. After ~5 seconds it goes to a deep 
> sleep/suspend. Writing anything to the serial will wake it up, the down side 
> is that the first command will be lost.
> 
> QAtChat:
> 	- This class can handle modems like the TI Calypso and can send a wakeup 
> command.
> 
> 
> So everything looks fine? Well, it depends on the wakeup command you send. The 
> existing code picked ATE0 which might or might not generate a response. So 
> the current code needs to discard everything that comes from the modem until 
> after a timeout (500msec) has passed. Well, everything but notifications 
> (first patch from me).
> 
> Now timing enters the stage. Qtopia starts qdsync which on our flash takes 
> quite a bit to start and somehow the QAtChat queue is blocked, sometimes we 
> manage to send a ATE0 (wakeup before starting qdsync) and the discard 
> interval passed without executing any code but we didn't process the input 
> from the modem.... So we get an OK as ATE0 response and treat it like the 
> response of the current command and things start to fail. We treat the output 
> of the previous command as the result of the current one...
> 
> Two solutions:
> 	- Send a command that does not generate a response. Mickeyl found one and is 
> happily using that for the TI Calypso in ogsmd and I copied that now.
> 
> 	- QAtChat::wakeupFinished might flush commands, or remove "OK" but getting 
> this right is really tricky. So the above solution is preferred.
> 
> 
> feedback is welcome, I've been running with these changes since saturday...


Holger,

Thanks for this great explanation of what's going on at this level. This 
type of understanding is excellent.

If you, or someone, had the time to wikify this information it would be 
wonderful.

Michael