[linux-dvb] HVR4000 Support

Darron Broad darron at kewl.org
Sun Mar 18 12:41:44 CET 2007

In message <1a297b360703180432v94b513bj441248b8a59a62c2 at mail.gmail.com>, "Manu Abraham" wrote:


>On 3/18/07, Darron Broad <darron at kewl.org> wrote:
>> In message <1a297b360703180407r63b1e98dj561ae0a0abc8188f at mail.gmail.com>, "Manu Abraham" wrote:
>> >On 3/18/07, Darron Broad <darron at kewl.org> wrote:
>> lo
>> >> >> 3. the delivery field has to be set
>> >> >>
>> >> >
>> >> >
>> >> >delivery system is set using DVBFE_SET_PARAMS, without which you
>> >> >wouldn't be able to tune to anything, because of the switch statement.
>> >>
>> >> the delivery type is indeed taken from the command line and used for
>> >> logic in the code, however, it's not passed to the driver.
>> >>
>> >
>> >It is. Take a look at the delsys switch in the stb0899 driver. The
>> >STB0899 depends on the delivery system and the Physical Layer
>> >parameters to decide which modulation to use.
>> >
>> >http://linuxtv.org/hg/~manu/stb0899-c5?f=d6f0bf7681d1;file=linux/drivers/media/dvb/frontends/stb0899_drv.c;sty
>> >gitweb
>> >The delivery system is sent to the driver, without which
>> >tuning/demodulation is impossible "on any multistandard demod"
>> specifically Steve's driver needs to the delivery system type
>> to be set when calling set_params.
>> it would appear from your code snippet that your driver is
>> setting internal state when peforming a query. surely this
>> is illogical behaviour.
>Sorry, nope. Since the IOCTL is RW not R

>#define DVBFE_GET_INFO _IOWR('o', 85, struct dvbfe_info)

please explain why you have chosen a function named GET
to SET internal state.

if you are expecting driver developers amd application programmers
to get confused then this is one way of achieving it.

my statement regarding illogical still holds. 

BTW, the unmodded szap only worked for you because it
queried the current state inadvertantly setting internal
state before calling set_params without actually specifying
the correct internal state.

if an application does a query and sets state to DVB-S2
then decides to tune to DVB-S the internal state will
be incorrect.



 // /
{:)==={ Darron Broad <darron at kewl.org>
 \\ \ 

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