[asterisk-bugs] [DAHDI-linux 0014104]: [patch] Generate VMWI line reversal from FXS module to light LED on newer 'non intellegent phone'

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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http://bugs.digium.com/view.php?id=14104 
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Reported By:                alecdavis
Assigned To:                dbailey
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Project:                    DAHDI-linux
Issue ID:                   14104
Category:                   wctdm
Reproducibility:            always
Severity:                   feature
Priority:                   normal
Status:                     assigned
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Date Submitted:             2008-12-18 02:36 CST
Last Modified:              2009-01-09 17:33 CST
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Summary:                    [patch] Generate VMWI line reversal from FXS module
to light LED on newer 'non intellegent phone'
Description: 
Added initial fundamental support to manipulate FXS line to generate
Message Waiting Indication. Still supports sending FSK as has been
supported for years.

Discovered undocumented parameter 'mwisendtype' in chan_dahdi.conf which
can only be 'rpas' Ring Pulse Alert Signal at the moment.

Intention is to use this field with parameters as follows;
   'fsk' or undefined for exisiting FSK only support.
   'none' no FSK spill heard every second time you go off hook.
   'rpas' for existing support ring pulse before FSK
   'lrev' line reversed while messages exist
   'hvdc' high voltage, 90Vdc idle voltage
   'hvac' high voltage neon generation, Following Silicb AN33

Alec


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 (0097399) alecdavis (reporter) - 2009-01-09 17:33
 http://bugs.digium.com/view.php?id=14104#c97399 
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For what it's worth regarding the wctdm patches.

I didn't like my logical XOR testing, it's not very readable, and when
compiled with 'cc -S xor_test.c' takes one more instruction.

The 2nd and 3rd method below compile to exacly the same instructions, but
I believe the 3rd method is most readable.

  result = ( !(!var1 != !var2) != !var3); /*12 instructions */
  printf("XOR var1=%d var2=%d var3=%d result=%d\n", var1, var2, var3,
result);

  result = (!!var1 ^ !!var2 ^ !!var3); /*11 instructions */
  printf("XOR var1=%d var2=%d var3=%d result=%d\n", var1, var2, var3,
result);

  result = ( (0!=var1) ^ (0!=var2) ^ (0!=var3) ); /*11 instructions */
  printf("XOR var1=%d var2=%d var3=%d result=%d\n", var1, var2, var3,
result); 

Issue History 
Date Modified    Username       Field                    Change               
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2009-01-09 17:33 alecdavis      Note Added: 0097399                          
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