TTY hangup AIX 3.2.5

ITEM: RTA000088974



Problem description:                                                            
A program communicates with a modem connected to tty1 (native s1 port).         
AIX oslevel = >3250. system= RISC 340H.                                         
The modem is programmed to keep DCD (pin8) "always on".                         
If the modem loses connection, in some cases the port hangs up.                 
If I kill the program with "kill -9" the program changes to            
but never terminates. Pin: cts rts dcd dtr are "ON" and Pin DSR is              
off, but nothing change if I force DSR ON.                                      
What can be done to prevent hanging ?? please see attached                      
output from crash for more detailed information on port status.                 
The problem is on tty1.                                                         
                                                                                
      (maj,min).chan.:    sid      grp  raw can out flags                       
      tty0:00002481 00002481   0   0   0 isopen iaslp ccnt=0                    
      tty1:00000000 00000000 489   0   2 isopen iclose stop iow ccnt=1         
      tty2:0000596d 0000596d   0   0   0 wopen ccnt=0                           
      tty3:000045e4 000045e4   0   0   0 wopen ccnt=0                           
      tty5:00002f92 00002f92   0   0   0 wopen ccnt=0                           
                                                                                
 tty1: tp=0x04fb79a0, dev:(16,1) chan:(0x0)                                     
 sid:0x00000000 group:0x00000000 tsm:0x00000000 id:1                            
 port status: isopen iclose stop iow ccnt=1                                     
 ctl=0x04f98280 lctl=0x05970300 hptr=0x04fb7880 evt=0x000047bc lck=0xff         
 rbuf: cc=0 ``''                                                                
 tbuf: cc=1 ``S''                                                              
 raw queue: cc=489, actual=489: ``UJUDMzUM-YfDwNMUMIM5EIDMJww..).          
 can queue: cc=0, actual=0: ``''                                                
 out queue: cc=2, actual=2: ``MJ''                                            
 ospeed=9600 ispeed=9600 stops=0 parity=0 csize=3                               
 char map=>0x01410cd0, ihog=512, ohog=512                                      
 rs discipline => I O S                                                         
 Unknown adapter in slot 15 at slih level 2                                     
 seg:0x82080060 port:0x00000038 iseg:0x820c0080 ibase:0x004f0000                
 slih queue: cc=0, actual=0: ``''                                               
 0 bytes for output at 0x4fd3def                                                
 xtal:24000000 rtrig:0xc0 tbc:16 posted:0 xmit:0 dma:0                          
 Last Modem Status: delta CTS, delta CD, CTS, DCD                               
 flags: open conf                                                               
 last 16 iir's: c0 c0 c0 c0 c0 c0 c0 c0 c0 c0 c0 c0 c0 c0 c0 c0                 
 dtropen discipline =>     S                                                    
 xon discipline => I O S                                                        
 posix discipline => I O S                                                      
 erase:M? kill:M? intrc:M? quitc:M? startc:Q stopc:S eofc:. eol:         
 eol2:M? suspc:M? dsuspc:M? rprntc:M? flushc:M? werasc:M? lnextc:         
 input:   ignpar ixon ixoff                                                    
 output:  nl0 cr0 tab0 bs0 vt0 ff0                                              
 cntrl:   b9600/ b9600 cs8 cread hupcl clocal                                   
 displn:                                                                        
 negotiated input:   ignpar ixon ixoff                                          
 negotiated output:  nl0 cr0 tab0 bs0 vt0 ff0                                   
 negotiated displn:                                                             
 select:                                                                        
 bits: vto carrier pinned block                                                 
 col = 0, rocount = 0, rocol = 0, ecount = 0                                    
 lead = 0, curlead = 0, curcount = 0, outleft = 0                               
 lead queue: cc=0, actual=0: ``''                                               
 canned quote queue: cc=0, actual=0: ``''                                       
 raw quote queue: cc=0, actual=0: ``''                                          
 dlytmr = 0x04f91a00, rawtmr = 0x04f91a40, vptr = 0x00000000                    
                                                                               
                                                                                
ANSWER                                                                          
Similar problems have been reported in the past and a large                     
PTF was created to correct multiple TTY problems.  I would                      
suggest that PTF U435110 be installed on the RISC System/6000.                  
This PTF was created after AIX version 3.2.5 came out to correct                
TTY problems that were occuring in the field.                                   
                                                                                
If the PTF does not correct the problem I would suggest looking                 
at the application.  If the application does not close the port                 
down in a clean fashion it can hang in an exiting state.                        
                                                                                
S e a r c h - k e y w o r d s:                                                  
MODEM HANG PTF                                                                  
                                                                               


WWQA: ITEM: RTA000088974 ITEM: RTA000088974
Dated: 12/1995 Category: ITSAI6000GE
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