From: Mauro Carvalho Chehab <mchehab@redhat.com>
To: Martin Rudge <martin.rudge@googlemail.com>
Cc: linux-media@vger.kernel.org
Subject: Re: DVB V5 API: Event Model
Date: Tue, 13 Nov 2012 07:24:14 -0200 [thread overview]
Message-ID: <50A211BE.60606@redhat.com> (raw)
In-Reply-To: <CAE-UT2ug=U4AJghXfXZBuBoa18JsPSjNsvHUEu9FHZvAm1qi1Q@mail.gmail.com>
Em 12-11-2012 11:04, Martin Rudge escreveu:
> Hello All,
>
> When using the V5 API (DVB-S/S2) for the DVB frontend device (with the
> now merged SEC functionality), setting properties DTV_VOLTAGE and/or
> DTV_TONE generates extra (unwanted?) events. This is due to utilising
> the legacy FE_SET_FRONTEND IOCTL in their respective implementations.
>
> Depending on their placement in one "atomic" FE_SET_PROPERTY call,
> they can cause an "incorrect" (premature) SYNC/LOCK event to be
> generated. For example, when looping issuing tune requests in
> succession during a scan operation. This was with a fairly recent
> media build (pulled Saturday).
I suspect that this is an undesirable behavior, likely there since the initial
version of DVB-S2 API. It could be too late to fix, as userspace apps may be
trusting on this behavior.
Maybe you could propose a patch and ask app developers what they thing about
it.
> Conversly using DTV_CLEAR clears the cached values, but doesn't affect
> the frontend (LNB). This is probably desirable behaviour.
This is desirable.
> Any thoughts, working as designed/intended?
Regards,
Mauro
next prev parent reply other threads:[~2012-11-13 9:24 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-12 13:04 DVB V5 API: Event Model Martin Rudge
2012-11-13 9:24 ` Mauro Carvalho Chehab [this message]
2012-11-14 9:47 ` Martin Rudge
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