On 2018-01-17 21:10, Brad Love wrote: > On 2018-01-17 20:36, Antti Palosaari wrote: >> On 01/18/2018 03:58 AM, Brad Love wrote: >>> On 2018-01-17 16:08, Brad Love wrote: >>>> On 2018-01-17 16:02, Antti Palosaari wrote: >>>>> On 01/17/2018 11:52 PM, Brad Love wrote: >>>>>> Some tuners produce inverted spectrum, but the si2168 is not >>>>>> currently set up to accept it. This adds an optional parameter >>>>>> to set the frontend up to receive inverted spectrum. >>>>>> >>>>>> Parameter is optional and only boards who enable inversion >>>>>> will utilize this. >>>>>> >>>>>> Signed-off-by: Brad Love <brad@xxxxxxxxxxxxxxxx> >>>>>> --- >>>>>> Changes since v1: >>>>>> - Embarassing build failure due to missing declaration. >>>>>> >>>>>> drivers/media/dvb-frontends/si2168.c | 3 +++ >>>>>> drivers/media/dvb-frontends/si2168.h | 3 +++ >>>>>> 2 files changed, 6 insertions(+) >>>>>> >>>>>> diff --git a/drivers/media/dvb-frontends/si2168.c >>>>>> b/drivers/media/dvb-frontends/si2168.c >>>>>> index c041e79..048b815 100644 >>>>>> --- a/drivers/media/dvb-frontends/si2168.c >>>>>> +++ b/drivers/media/dvb-frontends/si2168.c >>>>>> @@ -213,6 +213,7 @@ static int si2168_set_frontend(struct >>>>>> dvb_frontend *fe) >>>>>> struct i2c_client *client = fe->demodulator_priv; >>>>>> struct si2168_dev *dev = i2c_get_clientdata(client); >>>>>> struct dtv_frontend_properties *c = &fe->dtv_property_cache; >>>>>> + struct si2168_config *config = client->dev.platform_data; >>>>> hmmm, are you sure platform data pointer points is const? I usually >>>>> tend to store all config information to device state. Then there is no >>>>> need to care if pointer is valid or not anymore. >>>>> >>>>> And inversion happens when those wires are cross-connected >>>> It just dawned on me that the platform_data is stack allocated and >>>> therefore not safe to access outside of probe. I will fix this >>>> momentarily. >>>> >>>> I was informed by one of our hardware guys that the two models in patch >>>> 2/2 are inverted spectrum, so I guess they have wires >>>> cross-connected. I >>>> can verify this again to be sure. >>> >>> Hello Antti, >>> >>> I have confirmation. No 'cross-connected' / swapped differential pair >>> polarities (if that's what you meant) on the IF pins. The si2157 >>> inverted spectrum output is configurable though, and Hauppauge >>> have the tuner set up to output inverted. Sounds like it was a decision >>> based on interoperability with older demods. >> yeah, that was what I was thinking for. That board single tuner and >> two demods which other demod does not support if spectrum inversion? >> >> If there is just si2168 and si2157, you can set both to invert or both >> to non-invert - the end result is same. >> >> Antti > > I will check on the HVR975 tomorrow, if it's affected as well I'll > submit a patch. The lgdt3306a frontend is already set up for auto > spectrum inversion, so it is able handle the si2157 in either config. > The HVR975 should be good as currently submitted. Cheers, Brad
