[linux-dvb] [FIXEd] Bug Report - Twinhan vp-1020, bt_8xx driver + frontend

[Alain Turbide]

Good one Matthias.  Your first option seems like the most practical one and 
I can also confirm works.  1=HW, any other value   will set SW

----- Original Message ----- 
From: "Matthias Schwarzott" <zzam at gentoo.org>
To: <linux-dvb at linuxtv.org>
Cc: "Alain Turbide" <aturbide at rogers.com>
Sent: Tuesday, December 02, 2008 2:21 PM
Subject: Re: [linux-dvb] [FIXEd] Bug Report - Twinhan vp-1020, bt_8xx driver 
+ frontend


> On Dienstag, 2. Dezember 2008, Alain Turbide wrote:
>> Well, it's not a difficult fix now that I see it.  The issue was that the
>> original default for FE_ALGO_SW was 0 while FE_ALGO_HW was 1.
>> Since there is an older documented option for the dst module called
>> dst_algo that some people might still be using to force the tuning algo 
>> to
>> sofware by setting dst_algo=0, there is no choice but to also make the
>> default of DVBFE_ALGO_SW to also be 0 so that the values will match and 
>> the
>> new code will still function with users who force dst_algo=0 on the dst
>> module load.. The fix would thus be to go from: this in dvb_frontend.h
>> enum dvbfe_algo {
>>         DVBFE_ALGO_HW                   = (1 <<  0),
>>         DVBFE_ALGO_SW                   = (1 << 1),
>>         DVBFE_ALGO_CUSTOM               = (1 <<  2),
>>         DVBFE_ALGO_RECOVERY             = (1 << 31)
>> };
>>
>> to this:
>> enum dvbfe_algo {
>>         DVBFE_ALGO_HW                   = (1 <<  0),
>>         DVBFE_ALGO_SW                   = 0,
>>         DVBFE_ALGO_CUSTOM               = (1 <<  2),
>>         DVBFE_ALGO_RECOVERY             = (1 << 31)
>> };
>>
>> This is what I've done now and works well. This is the only change 
>> required
>> to fix the issue.   In dst.c we could also default dst_algo to
>> DVB_FRONTEND_SW instead of 0 to make it more robust.  I can't see any 
>> code
>> else where that depends on DVBFE_ALGO_SW being set to 2.
>>
>
> Why should we rely on exact values, and not just modify the only place 
> where
> these values are exposed to userspace, and change dst_get_tuning_algo to
> something similar to:
>
> static int dst_get_tuning_algo(struct dvb_frontend *fe)
> {
>        return dst_algo ? DVBFE_ALGO_HW : DVBFE_ALGO_SW;
> }
>
> The other (not backward compatible) fix is to adjust the parameter 
> description
> and use 1 and 2 as allowed settings.
>
> Regards
> Matthias 


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