[linux-dvb] [PATCH] Fix the min/max frequencies of some DVB-C frontends

Michael Krufky mkrufky at linuxtv.org
Mon Aug 6 21:12:10 CEST 2007


e9hack wrote:
> Michael Krufky schrieb:
>> Now I'm beginning to have doubts about Oliver's original patch:
>>
>> dvb_frontend: Range check of frequency and symbol rate
>> http://linuxtv.org/hg/v4l-dvb/rev/8186a34dd0a6
>>
>> Should we be checking fe->ops.tuner_ops.info.frequency_min|max , instead of
>> fe->ops.info.frequency_min|max ???
>>
> 
> I didn't see the ranges from the tuner, because the dvb-c drivers don't use the pll framework. They
> have very simple tuning functions only. We should use both values. One part may be more restrictive
> than the other one.
> 
> The intention to write the frequency patch was some trouble with w_scan, which starts on 50.5MHz.


FYI, I never mentioned "pll framework"

The DVB subsystem uses dvb_frontend tuner modules, in many, but not all cases.
This is used by silicon and pll tuners alike.

IMHO, if there is a separate tuner used in conjunction to the demod, it is
better to factor out the tuner to a separate dvb_frontend style module, rather
than leaving it hardcoded within the demod driver.  This may result in a benefit
of removal of duplicated code, in cases where multiple demods are using the same
tuner.  I don't know if this is the case in your situation, but it is the case
with many others.

Cheers,

Michael Krufky




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