dib3000mc signal strength

[matthieu castet <castet.matthieu@xxxxxxx>]

Hi,

I have a dvb-t usb2 device with a dib3000mc and the signal strength 
doesn't seem right : the value goes up and down.

The signal strength calculation is little strange :
- why does it use DIB3000MC_REG_SIGNAL_NOISE_LSB register ?
- the computing is strange : it remove bits 3 and 4 from the value.
- the comments are wrong : the dib3000mb signal_strength is different 
(there is a signal power register).

Any hints on that ?


Thanks

Matthieu


[1]
/* see dib3000mb.c for calculation comments */
static int dib3000mc_read_signal_strength(struct dvb_frontend* fe, u16 
*strength)
{
    struct dib3000_state* state = fe->demodulator_priv;
    u16 val = rd(DIB3000MC_REG_SIGNAL_NOISE_LSB);
    *strength = (((val >> 6) & 0xff) << 8) + (val & 0x3f);

    deb_stat("signal: mantisse = %d, exponent = %d\n",(*strength >> 8) 
& 0xff, *strength & 0xff);
    return 0;
}

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