[mythtv] Re: [mythtv-commits] mythtv commit: r7128 by danielk

[Allan Stirling]

Allan Stirling wrote:
> mythtv at cvs.mythtv.org wrote:
> 
>>       Author: danielk
>>         Date: 2005-08-25 01:37:37 +0000 (Thu, 25 Aug 2005)
>> New Revision: 7128
>>    Changeset: http://cvs.mythtv.org/trac/changeset/7128
>>
>> Modified:
>>
>>    trunk/mythtv/libs/libmythtv/dvbchannel.cpp
>>
>> Log:
>>
>> Another part of the "DVB channel flipping" fix.
>>
>> This flushes all DVB frontend events before tuning and then
>> waits for the first event after the tune.
>>
>> My first inclination would have been to wait for an event
>> with a status of FE_HAS_SIGNAL, but my card at least doesn't
>> send any events after the first one (with no flags) until there is a 
>> lock.
>>
> 
> After these event changes, I get no lock notification in an existing 
> transport scan.
> 
> I'm using a dvb-ttpci.
> 
> 2005-08-25 10:21:05.070 SIParser: Resetting all Table Handlers
> 2005-08-25 10:21:05.070 SIParser: SIParser Reset due to channel change
> 2005-08-25 10:21:05.073 DVB#0 Frequency: 10714250 Symbol Rate: 22000000 
> Pol: H/L Inv: Auto
> 2005-08-25 10:21:05.073 DVBEvents: Flushing Event 
> Status(Signal,Carrier,FEC Stable,Sync,Lock,) frequency(963491 Hz)
> 2005-08-25 10:21:05.074 DVB#0 DiSEqC 1.0 Switch - Port 0
> 
> If we look at how szap does it, it's waiting for:
> ioctl(fe_fd, FE_READ_STATUS, &status);
> ...
> if (exit_after_tuning && ((status & FE_HAS_LOCK) || (++timeout >= 10)))
>          break;
> 
> Yes, this isn't even as clean as polling for events.
> 
> I'll work on a patch later, if this is as simple as I think.
> 
> Cheers,
> 
> Allan.
> 
OK. A simplistic patch as in:

     fe_status_t status;
     int timeout = 0;

     while (true)
     {
         usleep(5000);
         if (ioctl(fd, FE_READ_STATUS, &status) == -1)
              return false;
         if (status & FE_HAS_LOCK)
              return true;
         if (++timeout >= 10)
              return false;
     }


replacing the event poll works. I know this isn't useful as-is, but it 
may help towards a resolution.

Cheers,

Allan