> > Basicly during the I2C operation that reads scancode, controller seems > > to stop processing input from IR sensor, resulting a loss of keypress. > > > > So the solution(?) I found was to decrease the udelay in > > ivtv_i2c_algo_template from 10 to 5. Guess it just doubles the frequency > > of ivtv i2c bus or something like that. Problem went away, IR controller > > is now working as expected. > > That's a long standing error in the ivtv driver. It ran the I2C bus at > 1/(2*10 usec) = 50 kHz instead of the standard 100 kHz. > > Technically any I2C device should be able to handle clock rates down to > about DC IIRC; so there must be a bug in the IR microcontroller > implementation. > > Also the CX23416 errantly marks its PCI register space as cacheable > which is probably wrong (see lspci output). This may also be > interfering with proper I2C operation with i2c_algo_bit depedning on the > PCI bridges in your system. > > > > > So question is: > > 1) Is it ok to decrease udelay for this board? > > Sure, I think. It would actually run the ivtv I2C bus at the nominal > clock rate specified by the I2C specification. > > I never had any reason to change it, as I feared causing regressions in > many well tested boards. > > > > 2) If yes, how to do it right? > > Try: > > # modprobe ivtv newi2c=1 > > to see if that works first. > udelay=10, newi2c=0 => BAD udelay=10, newi2c=1 => BAD udelay=5, newi2c=0 => OK udelay=5, newi2c=1 => BAD newi2c=1 also throws some log messages, not sure if its ok or not. Oct 5 11:41:16 moon kernel: [45430.916449] ivtv: Start initialization, version 1.4.1 Oct 5 11:41:16 moon kernel: [45430.916618] ivtv0: Initializing card 0 Oct 5 11:41:16 moon kernel: [45430.916628] ivtv0: Autodetected AVerTV MCE 116 Plus card (cx23416 based) Oct 5 11:41:16 moon kernel: [45430.918887] ivtv 0000:03:06.0: PCI INT A -> GSI 20 (level, low) -> IRQ 20 Oct 5 11:41:16 moon kernel: [45430.919229] ivtv0: i2c: i2c init Oct 5 11:41:16 moon kernel: [45430.919234] ivtv0: i2c: setting scl and sda to 1 Oct 5 11:41:16 moon kernel: [45430.937745] cx25840 0-0044: cx25843-23 found @ 0x88 (ivtv i2c driver #0) Oct 5 11:41:16 moon kernel: [45430.949145] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45430.951628] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45430.954191] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45430.956724] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45430.959211] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45430.961749] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45430.964236] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45430.966722] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45430.966786] ivtv0: i2c: i2c write to 43 failed Oct 5 11:41:16 moon kernel: [45430.971106] tuner 0-0061: chip found @ 0xc2 (ivtv i2c driver #0) Oct 5 11:41:16 moon kernel: [45430.974404] wm8739 0-001a: chip found @ 0x34 (ivtv i2c driver #0) Oct 5 11:41:16 moon kernel: [45430.986328] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45430.988871] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45430.991355] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45430.993904] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45430.996427] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45430.998938] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45431.001477] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45431.003968] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45431.004053] ivtv0: i2c: i2c write to 18 failed Oct 5 11:41:16 moon kernel: [45431.011333] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45431.013883] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45431.016418] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45431.018911] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45431.021463] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45431.023937] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45431.026478] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45431.028998] ivtv0: i2c: Slave did not ack Oct 5 11:41:16 moon kernel: [45431.029063] ivtv0: i2c: i2c write to 71 failed Oct 5 11:41:16 moon kernel: [45431.031468] ivtv0: i2c: Slave did not ack .... -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
