On 12/15/2012 12:31 AM, Patrice Chotard wrote:
Le 14/12/2012 18:55, Antti Palosaari a écrit :
On 12/14/2012 07:28 PM, Patrice Chotard wrote:
Before dvb_pll_attch call, be sure that drxd demodulator was
initialized, otherwise, dvb_pll_attach() will always failed.
In dvb_pll_attach(), first thing done is to enable the I2C gate
control in order to probe the pll by performing a read access.
As demodulator was not initialized, every i2c access failed.
Reported-by: frederic.mantegazza@xxxxxxxxxxx
Signed-off-by: Patrice Chotard <patricechotard@xxxxxxx>
---
drivers/media/pci/ngene/ngene-cards.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/media/pci/ngene/ngene-cards.c
b/drivers/media/pci/ngene/ngene-cards.c
index 96a13ed..e2192db 100644
--- a/drivers/media/pci/ngene/ngene-cards.c
+++ b/drivers/media/pci/ngene/ngene-cards.c
@@ -328,6 +328,8 @@ static int demod_attach_drxd(struct ngene_channel
*chan)
return -ENODEV;
}
+ /* initialized the DRXD demodulator */
+ chan->fe->ops.init(chan->fe);
if (!dvb_attach(dvb_pll_attach, chan->fe, feconf->pll_address,
&chan->i2c_adapter,
feconf->pll_type)) {
I don't like that as this causes again more deviation against normal
procedures. If gate open is needed (for probe or id check?) then
pll/tuner attach should open it. If that is not easily possible then
calling gate_control() before pll attach is allowed. init() is very,
very, bad as generally starts whole chip => starts eating power etc.
Even better would be to let whole gate-control to responsibility of
DVB-core, but unfortunately current situation is quite mess. Gate is
operated sometimes by DVB-core (like for init/sleep) and for some cases
it is left for responsibility of tuner driver. So on real life there is
mixed solutions and for init/sleep gate is even double controlled.
regards
Antti
Hi Antti,
Unfortunately, opening gate doesn't work with drxd demodulator before
its initialization (drxd_init() call).
Also, in dvb_pll_attach(), first thing done is opening the gate control.
I was aware by calling init() directly in demod_attach_drxd() was not
good at the power consumption point of view, but it was the only
solution to make it work.
To stop the power consumption, it would be possible to call the frontends :
}
+ /* initialized the DRXD demodulator */
+ chan->fe->ops.init(chan->fe);
if (!dvb_attach(dvb_pll_attach, chan->fe, feconf->pll_address,
&chan->i2c_adapter,
feconf->pll_type)) {
pr_err("No pll(%d) found!\n", feconf->pll_type);
return -ENODEV;
}
+ chan->fe->ops.sleep(chan->fe);
return 0;
}
Thanks for your feedback.
That one is better solution...
but it is clearly DRXD driver bug - it should offer working I2C gate
control after attach() :-( I looked quickly DRXD driver and there is
clearly some other places to enhance too. But I suspect there is no
maintainer, nor interest from anyone to start fix things properly, so
only reasonable way is to add that hack to get it working...
Honestly, I hate this kind of hacks :/ That makes our live hard on long
run. It goes slowly more and more hard to make any core changes as
regressions will happen due to this kind of hacks.
So send new patch which put demod chip sleeping after tuner attach. Or
even better, find out what is minimal set of commands needed do execute
during attach in order to offer working I2C gate (I suspect firmware
load is needed).
regards
Antti
--
http://palosaari.fi/
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