Re: tda18271 driver power consumption

[Antti Palosaari <crope@iki.fi>]

On 09/28/2012 12:58 AM, Michael Krufky wrote:
> On Thu, Sep 27, 2012 at 5:38 PM, Antti Palosaari <crope@iki.fi> wrote:
>> On 09/28/2012 12:20 AM, Michael Krufky wrote:
>>>
>>> On Thu, Sep 27, 2012 at 3:59 PM, Antti Palosaari <crope@iki.fi> wrote:
>>>>
>>>> On 09/27/2012 10:19 PM, Mauro Carvalho Chehab wrote:
>>>>>
>>>>>
>>>>> Em Thu, 26 Jul 2012 08:48:58 -0400
>>>>> Michael Krufky <mkrufky@linuxtv.org> escreveu:
>>>>>
>>>>>> Antti,
>>>>>>
>>>>>> This small patch should do the trick -- can you test it?
>>>>>>
>>>>>>
>>>>>> The following changes since commit
>>>>>> 0c7d5a6da75caecc677be1fda207b7578936770d:
>>>>>>
>>>>>>      Linux 3.5-rc5 (2012-07-03 22:57:41 +0300)
>>>>>>
>>>>>> are available in the git repository at:
>>>>>>
>>>>>>      git://git.linuxtv.org/mkrufky/tuners tda18271
>>>>>>
>>>>>> for you to fetch changes up to
>>>>>> 782b28e20d3b253d317cc71879639bf3c108b200:
>>>>>>
>>>>>>      tda18271: enter low-power standby mode at the end of
>>>>>> tda18271_attach() (2012-07-26 08:34:37 -0400)
>>>>>>
>>>>>> ----------------------------------------------------------------
>>>>>> Michael Krufky (1):
>>>>>>          tda18271: enter low-power standby mode at the end of
>>>>>> tda18271_attach()
>>>>>>
>>>>>>     drivers/media/common/tuners/tda18271-fe.c |    3 +++
>>>>>>     1 file changed, 3 insertions(+)
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> Mike,
>>>>>
>>>>> Despite patchwork's way of handling, thinking that this is a pull
>>>>> request,
>>>>> I suspect that your intention here were simply offer some patches for
>>>>> Antti
>>>>> to test.
>>>>>
>>>>> In any case, please always send the patches via email to the ML before
>>>>> sending a pull request. This was always a rule, but some developers are
>>>>> lazy with this duty, and, as I didn't use to have a tool to double
>>>>> check,
>>>>> bad things happen.
>>>>>
>>>>> I'm now finally able to check with a simple script if weather a patch
>>>>> went to the ML or not. My script checks both reply-to/references email
>>>>> tags and it looks for the same patch subject at the ML Inbox.
>>>>> So, I'll be now be more grumpy with that ;) [1]
>>>>>
>>>>> So, please be sure to post those patches at the ML, with Antti's
>>>>> tested-by:
>>>>> tag, before sending a pull request.
>>>>>
>>>>> Thanks!
>>>>> Mauro
>>>>>
>>>>> [1] Side note: it is not actually a matter of being grumpy; posted
>>>>> patches
>>>>> receive a lot more attention/review than simple pull requests. From time
>>>>> to time, patches that went via the wrong way (e. g. without a previous
>>>>> post)
>>>>> caused troubles for other developers. So, enforcing it is actually a
>>>>> matter
>>>>> of improving Kernel quality and avoiding regressions.
>>>>>
>>>>> -
>>>>>
>>>>> $ test_patch
>>>>> testing if
>>>>> patches/0001-tda18271-enter-low-power-standby-mode-at-the-end-of-.patch
>>>>> applies
>>>>> patch -p1 -i
>>>>> patches/0001-tda18271-enter-low-power-standby-mode-at-the-end-of-.patch
>>>>> --dry-run -t -N
>>>>> patching file drivers/media/tuners/tda18271-fe.c
>>>>>     drivers/media/tuners/tda18271-fe.c |    3 +++
>>>>>     1 file changed, 3 insertions(+)
>>>>> Subject: tda18271: enter low-power standby mode at the end of
>>>>> tda18271_attach()
>>>>> From: Michael Krufky <mkrufky@linuxtv.org>
>>>>> Date: Thu, 26 Jul 2012 08:34:37 -0400
>>>>> Patch applies OK
>>>>> total: 0 errors, 0 warnings, 9 lines checked
>>>>>
>>>>> patches/0001-tda18271-enter-low-power-standby-mode-at-the-end-of-.patch
>>>>> has no obvious style problems and is ready for submission.
>>>>> Didn't find any message with subject equal to 'tda18271: enter low-power
>>>>> standby mode at the end of tda18271_attach()'
>>>>> Duplicated md5sum patches
>>>>> Likely duplicated patches (need manual check)
>>>>
>>>>
>>>>
>>>> If that tda18271 patch is not applied then these two should be:
>>>>
>>>> https://patchwork.kernel.org/patch/1481901/
>>>> https://patchwork.kernel.org/patch/1481911/
>>>>
>>>>
>>>> regards
>>>> Antti
>>>>
>>>> --
>>>> http://palosaari.fi/
>>>
>>>
>>> The tda18271 patch should indeed be applied -- I will send it to the
>>> ML later on today and follow up with a pull request.  Thanks to all
>>> who have commented :-)
>>
>>
>> Mike, There is other problem too. PCTV 520e, which is Em28xx + DRX-K +
>> TDA18271, fails to attach tuner now. Tuner is wired behind DRX-K I2C bus.
>> TDA18271 driver does very much I/O during attach and I2C error is raised
>> during attach now. Earlier it worked as DRX-K firmware was downloaded before
>> tuner was attached, but now both DRX-K fw download and tuner attach happens
>> same time leading that error.
>
> Why is the DRX-K firmware downloading at the same time as tuner
> attach?  Shouldn't the demod attach be finished before the tuner
> attach begins?

What I think all these should go in order bridge => demod => tuner. 
Attach and fw loading. I cannot see how it will never work generally 
unless those firmwares are loaded in that order.
1) bridge needs firmware up and running before demod could be attached. 
That is mostly because I2C adapter is behind bridge.

2) demod needs firmware up and running before tuner could be attached. 
That is mostly because I2C adapter/bus for tuner is behind the demod.

3) tuner needs firmware up and running as there could be firmware 
controlled GPIO bus behind tuner. There is many times LNA, LNB 
controller, LED, antenna switch. I am not surprised if there is even I2C 
bus behind the tuner to control LNB or other equipment near antenna 
connector and tuner.

Of course situation is not that bad usually - but surely there could be 
some existing device which is very near that. But as we *want* to do 
things as general as possible to avoid driver / device specific hacks 
that is the only reasonable model.

regards
Antti

-- 
http://palosaari.fi/