On Sun, 2013-01-06 at 20:45 +0200, Antti Palosaari wrote:
> On 01/06/2013 08:14 PM, Malcolm Priestley wrote:
> > On Sun, 2013-01-06 at 15:37 +0200, Antti Palosaari wrote:
> >> On 01/06/2013 02:40 PM, Malcolm Priestley wrote:
> >>> Restore ds3000.c read_signal_strength.
> >>>
> >>> Call tuner get_rf_strength from frontend read_signal_strength.
> >>>
> >>> We are able to do a NULL check and doesn't limit the tuner
> >>> attach to the frontend attach area.
> >>>
> >>> At the moment the lmedm04 tuner attach is stuck in frontend
> >>> attach area.
> >>
> >> I would like to nack that, as I see some problems:
> >> 1) it changes deviation against normal procedures
> >> 2) interface driver (usb/pci) should have full control to make decision
> >> 3) you shoot to our own leg easily in power management
> >>
> > This patch does not do any operational changes, and is a proper way to
> > call to another module with a run time NULL check. The same way as
> > another tuner function from demodulator is called.
>
> uh, certainly I understand it does not change functionality in that
> case! I tried to point out it is logically insane and error proof. Ee
> should make this kind of direct calls between drivers as less as
> possible - just to make life easier in future. It could work for you,
> but for some other it could cause problems as hardware is designed
> differently.
>
> >> * actually bug 3) already happened some drivers, like rtl28xxu. Tuner is
> >> behind demod and demod is put sleep => no access to tuner. FE callback
> >> is overridden (just like you are trying to do as default) which means
> >> user-space could still make queries => I/O errors.
> >
> > In such cases, the tuner init/sleep should also be called.
>
> ???????
> I think you don't understand functionality at all!
>
Please, I have been working with the I2C bus in the electronics field
for the last 20 years.
If you are really worried about the the tuner being a sleep. You add
fe variable check this in it's own init/sleep and define the function
something like this.
static int fe_foo_read_signal_strength(struct dvb_frontend *fe,
u16 *strength)
{
struct fe_foo_state *state = fe->demodulator_priv;
if (state->fe_inactive) {
... any extra commands to restore tuner power
if (fe->ops.tuner_ops.init)
fe->ops.tuner_ops.init(fe);
}
if (fe->ops.tuner_ops.get_rf_strength)
fe->ops.tuner_ops.get_rf_strength(fe, strength);
if (state->fe_inactive) {
if (fe->ops.tuner_ops.sleep)
fe->ops.tuner_ops.sleep(fe);
... any extra commands to remove tuner power
}
return 0;
}
However, I think this is unnecessary in the rs2000 and ds3000.
Regards
Malcolm
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