linux-kernel - Re: [PATCH] media: em28xx-dvb unregister i2c tuner and demod after fe detach

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Date:	Tue, 15 Jul 2014 20:36:46 +0300
From:	Antti Palosaari <crope@....fi>
To:	shuah.kh@...sung.com, m.chehab@...sung.com
CC:	linux-media@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] media: em28xx-dvb unregister i2c tuner and demod after
 fe detach

Moikka!

On 07/15/2014 08:29 PM, Shuah Khan wrote:
> On 07/12/2014 02:14 PM, Antti Palosaari wrote:
>> Moikka Shuah!
>> I suspect that patch makes no sense. On DVB there is runtime PM
>> controlled by DVB frontend. It wakes up all FE sub-devices when frontend
>> device is opened and sleeps when closed.
>>
>> FE release() is not relevant at all for those sub-devices which are
>> implemented as a proper I2C client. I2C client has own remove() for that.
>>
>> em28xx_dvb_init and em28xx_dvb_fini are counterparts. Those I2C drivers
>> are load on em28xx_dvb_init so logical place for unload is
>> em28xx_dvb_fini.
>>
>> Is there some real use case you need that change?
>>
>> regards
>> Antti
>>
>
> Hi Antti,
>
> The reason I made this change is because dvb_frontend_detach()
> calls release interfaces for fe as well as tuner. So it made
> sense to move the remove after that is all done. Are you saying
> fe and tuner release calls aren't relevant when sub-devices
> implement a proper i2c client? If that is the case then, and
> there is no chance for these release calls to be invoked when a
> proper i2c is present, then my patch isn't needed.

Yes, that is just case. Proprietary DVB binding model uses attach / 
release, but I2C binding model has probe / remove. I see no reason use 
DVB proprietary model, instead drivers should be converted to kernel I2C 
model.

regards
Antti

-- 
http://palosaari.fi/
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