Statemachine: wait for many types

[Osma Suominen]

Hello again,

this time I have a question concerning the statemachine code
(common/gsm-statemachine.c). There is a very useful function sm_block
and several variants of it, which all wait for a message of a certain
type to come from the phone.

However, the 3110 protocol is such that the phone usually has different
return codes (i.e. message types) to indicate a succesful and a failed
operation. Thus e.g. 0x28 is "SMS sent OK" and 0x29 is "SMS send error".

The problem is that the driver code doesn't know beforehand if the
operation will succeed or not, so it has to wait for either of the two
messages to appear. sm_block(), however, only takes a single expected
message type as argument. This means that it can't be used for this
purpose and lower level statemachine functions have to be used instead.
In practice almost identical copies of the sm_block_timeout() function
appear in the 3110 driver in many places, and more will come if the 3110
driver functionality is expanded (e.g. phonebook handling). That is pure
copy-paste coding and very ugly.

Now one way of fixing this would be to make a private wrapper function
in the 3110 code, but I think that's not actually the right place for
it, because the supposed sm_block_many() function is not in any way
specific to the 3110 except that other drivers currently don't seem to
need that kind of functionality.

To get to the point, I'd like to add a sm_block_many function to
gsm-statemachine.c, and also perhaps some other variants of it. Now the
cleanest way of doing this (with the least code duplication) is to
rewrite the current sm_block_timeout() into a generalized one, say,
sm_block_many_timeout(), that accepts an array of message types instead
of one, and make the other functions use that internally (of course,
with a new sm_block_timeout() that takes just one, for compatibility).

Is this acceptable to you? If it is, I'll be glad to submit a patch,
because it makes 3110 maintenance a lot easier for me.

-Osma
(no flooding of the list today for me anymore...)

-- 
*** Osma Suominen *** address@hidden *** http://www.iki.fi/ozone/ ***