[asterisk-bugs] [DAHDI-linux 0014577]: [patch] FXO channels "hookstate" incorrect on startup

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=14577 
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Reported By:                jkroon
Assigned To:                sruffell
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Project:                    DAHDI-linux
Issue ID:                   14577
Category:                   dahdi (the module)
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     confirmed
JIRA:                        
Reviewboard Link:            
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Date Submitted:             2009-03-01 16:16 CST
Last Modified:              2010-03-09 04:26 CST
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Summary:                    [patch] FXO channels "hookstate" incorrect on
startup
Description: 
Referencing bug 13786 (http://bugs.digium.com/view.php?id=13786) which
attempts to work around an underlying problem in userspace (chan_dahdi). 
The issue seems to be (as described by tzafrir):

It seems to expose a bug(?) in zaptel/dahdi where chan->rxhooksig is set
to RX_HOOKSIG_INITIAL at the end of chanconfig() which leaves the channel's
state there "uninitialized" and even if the channel driver knows better it
cannot override this decision. But I'm not sure what's the intended
behaviour, so I avoid a seperate bug report on that for now.

This is manifested in that I cannot make outbound calls on an FXO card
(Using FXSKS signalling) until I've received an incoming call resetting the
hookstate to offhook (A single ring is good enough), or alternatively,
disconnecting and reconnecting the telephone line.
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Relationships       ID      Summary
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has duplicate       0015429 After the system reboot calls do not go...
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 (0119173) tzafrir (manager) - 2010-03-09 04:26
 https://issues.asterisk.org/view.php?id=14577#c119173 
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Looking at the Asterisk side again.

In the case of FXOKS / FXOGS channels, Asterisk currently checks the
'rxbits' field returned from the channel ioctl DAHDI_GET_PARAMS. That field
is set to -1 if CAS is not used, and to the rx bits if CAS is used.

But Asterisk goes along and decides that the channel is available if the
value of that field > -1 . That is: if this is a CAS channel, the value of
rxisoffhook is ignored.

For analog channels we already know that it's pointless as the channel
alarm replaces it.

Patch asterisk-162-14577-onlycas.diff includes the suggested fix. For
Asterisk 1.6.2  SVN r249844 . (trunk is not usable right now to debug those
issues, due to the near-by issue 16983). 

Issue History 
Date Modified    Username       Field                    Change               
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2010-03-09 04:26 tzafrir        Note Added: 0119173                          
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