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

Michael Ira Krufky
2015-07-30T11:37:47Z

On Thu, Jul 30, 2015 at 7:14 AM, Michael Ira Krufky <mkrufky@linuxtv.org> wrote:
> On Thu, Jul 30, 2015 at 6:08 AM, Joe Perches <joe@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@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@perches.com>
>
> Reviewed-by: Michael Ira Krufky <m.krufky@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?

-Michael Ira Krufky