On 27.12.2011 14:28, Mauro Carvalho Chehab wrote:
> On 27-12-2011 10:11, Andreas Oberritter wrote:
>> On 27.12.2011 02:07, Mauro Carvalho Chehab wrote:
>>> DVB-S and DVB-T, as those were the standards supported by DVBv3.
>>
>> The description seems to be incomplete.
>>
>>> New standards like DSS, ISDB and CTTB don't fit on any of the
>>> above types.
>>>
>>> while there's a way for the drivers to explicitly change whatever
>>> default DELSYS were filled inside the core, still a fake value is
>>> needed there, and a "compat" code to allow DVBv3 applications to
>>> work with those delivery systems is needed. This is good for a
>>> short term solution, while applications aren't using DVBv5 directly.
>>>
>>> However, at long term, this is bad, as the compat code runs even
>>> if the application is using DVBv5. Also, the compat code is not
>>> perfect, and only works when the frontend is capable of auto-detecting
>>> the parameters that aren't visible by the faked delivery systems.
>>>
>>> So, let the frontend fill the supported delivery systems at the
>>> device properties directly, and, in the future, let the core to use
>>> the delsys to fill the reported info::type based on the delsys.
>>>
>>> Signed-off-by: Mauro Carvalho Chehab <mche...@redhat.com>
>>> ---
>>> drivers/media/dvb/dvb-core/dvb_frontend.c | 13 +++++++++++++
>>> drivers/media/dvb/dvb-core/dvb_frontend.h | 8 ++++++++
>>> 2 files changed, 21 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/drivers/media/dvb/dvb-core/dvb_frontend.c
>>> b/drivers/media/dvb/dvb-core/dvb_frontend.c
>>> index 8dedff4..f17c411 100644
>>> --- a/drivers/media/dvb/dvb-core/dvb_frontend.c
>>> +++ b/drivers/media/dvb/dvb-core/dvb_frontend.c
>>> @@ -1252,6 +1252,19 @@ static void dtv_set_default_delivery_caps(const
>>> struct dvb_frontend *fe, struct
>>> const struct dvb_frontend_info *info = &fe->ops.info;
>>> u32 ncaps = 0;
>>>
>>> + /*
>>> + * If the frontend explicitly sets a list, use it, instead of
>>> + * filling based on the info->type
>>> + */
>>> + if (fe->ops.delsys[ncaps]) {
>>> + while (fe->ops.delsys[ncaps] && ncaps < MAX_DELSYS) {
>>> + p->u.buffer.data[ncaps] = fe->ops.delsys[ncaps];
>>> + ncaps++;
>>> + }
>>> + p->u.buffer.len = ncaps;
>>> + return;
>>> + }
>>> +
>>
>> I don't understand what this is trying to solve. This is already handled
>> by the get_property driver callback.
>>
>> dtv_set_default_delivery_caps() only sets some defaults for drivers not
>> implementing get_property yet.
>
> dtv_set_default_delivery_caps() does the wrong thing for delivery systems
> like ISDB-T, ISDB-S, DSS, DMB-TH, as it fills data with a fake value that
> is there at fe->ops.info.type.
>
> The fake values there should be used only for DVBv3 legacy calls emulation
> on those delivery systems that are not fully compatible with a DVBv3 call.
That's right. Still, there's no need to introduce fe->ops.delsys,
because the drivers in question could just implement get_property
instead. At least that's what we discussed and AFAIR agreed upon when
Manu recently submitted his patches regarding enumeration of delivery
systems.
> At the end, I think we should deprecate the fe->ops.info.type, as its
> contents is not reliable (as it can represent something else).
>
> Btw, there are several places at dvb_frontend.c that uses the info.type
> to assume the delivery system. This leads DVB core to do the wrong assumptions
> for non-DVBv3 supported systems. The right way is to use a new field that
> really represents the supported delivery systems by a given frontend, instead
> of relying on fe->ops.info.type.
>
>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-media" in
>> the body of a message to majord...@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
