[asterisk-bugs] [DAHDI-linux 0013205]: [patch] bad master selection

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=13205 
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Reported By:                biohumanoid
Assigned To:                sruffell
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Project:                    DAHDI-linux
Issue ID:                   13205
Category:                   dahdi (the module)
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     assigned
JIRA:                        
Reviewboard Link:            
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Date Submitted:             2008-07-31 00:11 CDT
Last Modified:              2011-02-15 22:59 CST
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Summary:                    [patch] bad master selection
Description: 
Current dahdi master handling work in the following way:
The first SPAN become a master
If a new registered !!! SPAN is preferred , it is the new master
If a span is unregistered - the new master is the first available span
If master SPAN is in alarm state - the new master is the first non in
alarm state SPAN

So
1. dahdi-dummy once loaded will be the master forever.
2. even not-running SPAN can be a master
3. master implementation is ugly...
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Relationships       ID      Summary
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related to          0013206 [patch] ztdynamic double buffering on r...
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 (0132000) biohumanoid (reporter) - 2011-02-15 22:59
 https://issues.asterisk.org/view.php?id=13205#c132000 
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Sorry gentlemen I've left this discussion for a time.

Glad to see you've started patching master selection code.
Even this simple will make life easier, and will be a good starting
point.

I have some things to ask/note about (__dahdi_find_master_span):
1. Why don't you check span->alarms for alarms ?
Not sure which condition is better, 
!span->alarms 
or 
!(span->alarms & (DAHDI_ALARM_RED | DAHDI_ALARM_BLUE |
DAHDI_ALARM_LOOPBACK))

2.Why do you specially care about analog cards ?
The do have an oscillator, and it's customers choice to use it or not to
use it as a timing source for DAHDI.

3. Why don't you try to avoid dahdi_dummy as a sync master ?
!span->channels
You still have dahdi_dummy module, and it's good (I'll write a bit later)

4. can_provide_timing – what for ?
dahdy_dynamic_loc &= ~DAHDI_FLAG_RUNNING
and it will not be the master...

5. pref_master not used

I'll tell you my vision on synchronization in a few next posts, based on
my experience/troubles.
I don't insist I'm right, no way. 

Issue History 
Date Modified    Username       Field                    Change               
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2011-02-15 22:59 biohumanoid    Note Added: 0132000                          
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