[PATCH 02/12] [media] dvb-pll: Add support for THOMSON DTT7546X tuner.

[Peter Griffin]

Hi Michael,

On Thu, 30 Jul 2015, Michael Ira Krufky wrote:

> On Thu, Jul 30, 2015 at 7:14 AM, Michael Ira Krufky <mkrufky at linuxtv.org> wrote:
> > On Thu, Jul 30, 2015 at 6:08 AM, Joe Perches <joe at perches.com> wrote:
> >> On Thu, 2015-07-30 at 10:47 +0100, Peter Griffin wrote:
> >>> Hi Mauro / Joe,
> >>>
> >>> On Wed, 22 Jul 2015, Mauro Carvalho Chehab wrote:
> >>>
> >>> > Em Wed, 24 Jun 2015 18:17:37 -0700
> >>> > Joe Perches <joe at perches.com> escreveu:
> >>> >
> >>> > > On Wed, 2015-06-24 at 16:11 +0100, Peter Griffin wrote:
> >>> > > > This is used in conjunction with the STV0367 demodulator on
> >>> > > > the STV0367-NIM-V1.0 NIM card which can be used with the STi
> >>> > > > STB SoC's.
> >>> > >
> >>> > > Barely associated to this specific patch, but for
> >>> > > dvb-pll.c, another thing that seems possible is to
> >>> > > convert the struct dvb_pll_desc uses to const and
> >>> > > change the "entries" fixed array size from 12 to []
> >>> > >
> >>> > > It'd save a couple KB overall and remove ~5KB of data.
> >>> > >
> >>> > > $ size drivers/media/dvb-frontends/dvb-pll.o*
> >>> > >    text      data     bss     dec     hex filename
> >>> > >    8520      1552    2120   12192    2fa0 drivers/media/dvb-frontends/dvb-pll.o.new
> >>> > >    5624      6363    2120   14107    371b drivers/media/dvb-frontends/dvb-pll.o.old
> >>> >
> >>> > Peter,
> >>> >
> >>> > Please add this patch on the next patch series you submit.
> >>>
> >>> Ok will do, I've added this patch with a slightly updated commit message
> >>> to my series.
> >>>
> >>> Joe - Can I add your signed-off-by?
> >>
> >> Signed-off-by: Joe Perches <joe at perches.com>
> >
> > Reviewed-by: Michael Ira Krufky <m.krufky at samsung.com>
> >
> > Joe, nice optimization - thanks for that.
> >
> > With regards to Peter's patch, is this a digital-only tuner, or is it
> > a hybrid tuner?
> >
> > The 5th byte that you send to the THOMSON DTT7546X seems to resemble
> > the 'auxiliary byte' that gets set in tuner-simple.c
> >
> > I'm not sure that dvb-pll is the right place for this tuner
> > definition, if this is the case.  Maybe this definition belongs in
> > tuner-simple instead, if the pattern matches better there.
> >
> > Mauro, can we hold off on merging Peter's patch until we resolve this?
> 
> This code block, specifically, I would rather not see added into dvb-pll:
> 
> +static int dvb_pll_get_num_regs(struct dvb_pll_priv *priv)
> +{
> +       int num_regs = 4;
> +
> +       if (strncmp(priv->pll_desc->name, "Thomson dtt7546x", 16) == 0)
> +               num_regs = 5;
> +
> +       return num_regs;
> +}
> +
> 
> tuner-simple provides an infrastructure that allows this tuner to be
> added in a more elegant way without the need to add special cases to
> otherwise generic code, as done in the above.
> 
> I'm sorry, Peter.  Can you take a look at tuner-simple and consider
> sending a new patch?

Yes sure. I wasn't actually aware that tuner-simple existed. From what I
can see briefly looking at it, it does look a more suitable way of adding
support for this tuner.

The dtt7546x is a dual tuner in that it supports dvb-t and dvb-c, however
I have only tested it with DVB-T as that is the only feed I have to my home office.

As I have a V2 incorporating all of Mauro's changes ready to send, and I'm 
on holiday for 3 weeks from Friday, I will temporarily drop support for this
tuner and NIM card in V2, and migrate over to the new driver when I return end
of August.

regards,

Peter.