From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.kapsi.fi ([217.30.184.167]:34891 "EHLO mail.kapsi.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752382Ab3AAQnw (ORCPT ); Tue, 1 Jan 2013 11:43:52 -0500 Message-ID: <50E31220.5060405@iki.fi> Date: Tue, 01 Jan 2013 18:43:12 +0200 From: Antti Palosaari MIME-Version: 1.0 To: Mauro Carvalho Chehab CC: Linux Media Mailing List Subject: Re: [RFC PATCH] [media] dvb: frontend API: Add a flag to indicate that get_frontend() can be called References: <1356738146-9352-1-git-send-email-mchehab@redhat.com> In-Reply-To: <1356738146-9352-1-git-send-email-mchehab@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 12/29/2012 01:42 AM, Mauro Carvalho Chehab wrote: > get_frontend() can't be called too early, as the device may not have it > yet. Yet, get_frontend() on OFDM standards can happen before FE_HAS_LOCK, > as the TMCC carriers (ISDB-T) or the TPS carriers (DVB-T) require a very > low signal to noise relation to be detected. The other carriers use > different modulations, so they require a higher SNR. I would like to questionable need of whole flag. Is there really need to separate FE_HAS_PARAMETERS from FE_HAS_LOCK as we are not still making the professional DTV analyzing equipment? And on the other-hand, I don't see any change for DVB-core which syncs cache when FE_HAS_PARAMETERS is set. What I remember current behavior of DVB-core is to call get_frontend() after FE_HAS_LOCK is set and as that patch does not change it => there is likely implementation bug too. regards Antti > > Signed-off-by: Mauro Carvalho Chehab > --- > Documentation/DocBook/media/dvb/frontend.xml | 13 ++++++++++++- > drivers/media/dvb-frontends/mb86a20s.c | 17 ++++++++++------- > include/uapi/linux/dvb/frontend.h | 4 ++++ > 3 files changed, 26 insertions(+), 8 deletions(-) > > v3: rebase it to apply with current tip and add an implementation example. > > Obsoletes: http://patchwork.linuxtv.org/patch/13783/ > > diff --git a/Documentation/DocBook/media/dvb/frontend.xml b/Documentation/DocBook/media/dvb/frontend.xml > index 426c252..5feff4e 100644 > --- a/Documentation/DocBook/media/dvb/frontend.xml > +++ b/Documentation/DocBook/media/dvb/frontend.xml > @@ -216,6 +216,7 @@ typedef enum fe_status { > FE_HAS_LOCK = 0x10, > FE_TIMEDOUT = 0x20, > FE_REINIT = 0x40, > + FE_HAS_PARAMETERS = 0x80, > } fe_status_t; > > to indicate the current state and/or state changes of the frontend hardware: > @@ -244,7 +245,17 @@ typedef enum fe_status { > FE_REINIT > The frontend was reinitialized, application is > recommended to reset DiSEqC, tone and parameters > - > + > +FE_HAS_PARAMETERS > + > +FE_GET_PROPERTY/FE_SET_PROPERTY or > +FE_GET_FRONTEND can now be > +called to provide the detected network parameters. > +This should be risen for example when the DVB-T TPS/ISDB-T TMCC is locked. > +This status can be risen before FE_HAS_SYNC, as the SNR required for > +parameters detection is lower than the requirement for the other > +carriers on the OFDM delivery systems. > + > > > > diff --git a/drivers/media/dvb-frontends/mb86a20s.c b/drivers/media/dvb-frontends/mb86a20s.c > index fade566..35153b6 100644 > --- a/drivers/media/dvb-frontends/mb86a20s.c > +++ b/drivers/media/dvb-frontends/mb86a20s.c > @@ -333,19 +333,22 @@ static int mb86a20s_read_status(struct dvb_frontend *fe, fe_status_t *status) > fe->ops.i2c_gate_ctrl(fe, 1); > > if (val >= 2) > - *status |= FE_HAS_SIGNAL; > + *status |= FE_HAS_SIGNAL; /* Tuner locked */ > > if (val >= 4) > - *status |= FE_HAS_CARRIER; > + *status |= FE_HAS_CARRIER; /* Mode reliably detected */ > > - if (val >= 5) > - *status |= FE_HAS_VITERBI; > + if (val >= 6) > + *status |= FE_HAS_VITERBI; /* PLL locked and broadband detected */ > > if (val >= 7) > - *status |= FE_HAS_SYNC; > + *status |= FE_HAS_SYNC; /* Frame sync */ > > - if (val >= 8) /* Maybe 9? */ > - *status |= FE_HAS_LOCK; > + if (val >= 8) > + *status |= FE_HAS_PARAMETERS; /* TMCC locked */ > + > + if (val >= 9) > + *status |= FE_HAS_LOCK; /* TS output started */ > > dprintk("val = %d, status = 0x%02x\n", val, *status); > > diff --git a/include/uapi/linux/dvb/frontend.h b/include/uapi/linux/dvb/frontend.h > index c12d452..e4daeee 100644 > --- a/include/uapi/linux/dvb/frontend.h > +++ b/include/uapi/linux/dvb/frontend.h > @@ -132,6 +132,9 @@ typedef enum fe_sec_mini_cmd { > * @FE_TIMEDOUT: no lock within the last ~2 seconds > * @FE_REINIT: frontend was reinitialized, application is recommended > * to reset DiSEqC, tone and parameters > + * @FE_HAS_PARAMETERS: get_frontend() can now be called to provide the > + * detected network parameters. This should be risen > + * for example when the DVB-T TPS/ISDB-T TMCC is locked. > */ > > typedef enum fe_status { > @@ -142,6 +145,7 @@ typedef enum fe_status { > FE_HAS_LOCK = 0x10, > FE_TIMEDOUT = 0x20, > FE_REINIT = 0x40, > + FE_HAS_PARAMETERS = 0x80, > } fe_status_t; > > typedef enum fe_spectral_inversion { > -- http://palosaari.fi/