Re: [PATCH v7 1/2] [media] atmel-isc: add the Image Sensor Controller code

From	Hans Verkuil <hverkuil@xs4all.nl>
Newsgroups	linux.kernel
Subject	Re: [PATCH v7 1/2] [media] atmel-isc: add the Image Sensor Controller code
Date	2016-08-02 09:40 +0200
Message-ID	<s1CsV-1on-5@gated-at.bofh.it> (permalink)
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On 08/02/2016 08:20 AM, Wu, Songjun wrote:
>>> +static unsigned int sensor_preferred = 1;
>>> +module_param(sensor_preferred, uint, S_IRUGO|S_IWUSR);
>>> +MODULE_PARM_DESC(sensor_preferred,
>>> +		 "Sensor is preferred to output the specified format (1-on 0-off) default 1");
>>
>> I have no idea what this means. Can you elaborate? Why would you want to set this to 0?
>>
> ISC can convert the raw format to the other format, e.g. YUYV.
> If we want to output YUYV format, there are two choices, one is the 
> sensor output YUYV format, ISC bypass the data to the memory, the other 
> is the sensor output raw format, ISC convert raw format to YUYV.
> 
> So I provide a module parameter to user to select.
> I prefer to select the sensor to output the specified format, then I set 
> this parameter to '1', not '0'.

Does this only apply to YUYV?

The reason I am hesitant about this option is that I am not convinced you need
it. The default (sensor preferred) makes sense and that's what other drivers
do as well. Unless you know of a real use-case where you want to set this to 0,
I would just drop this option.

If there *is* a real use-case, then split off adding this module option into a
separate patch so we can discuss it more without blocking getting this driver
into mainline. I don't like the way this is done here.

Regards,

	Hans

Thread

[PATCH v7 0/2] [media] atmel-isc: add driver for Atmel ISC Songjun Wu <songjun.wu@microchip.com> - 2016-07-29 10:10 +0200
  Re: [PATCH v7 1/2] [media] atmel-isc: add the Image Sensor Controller  code Hans Verkuil <hverkuil@xs4all.nl> - 2016-08-01 11:50 +0200
    Re: [PATCH v7 1/2] [media] atmel-isc: add the Image Sensor Controller  code "Wu, Songjun" <Songjun.Wu@microchip.com> - 2016-08-02 08:30 +0200
      Re: [PATCH v7 1/2] [media] atmel-isc: add the Image Sensor Controller  code Hans Verkuil <hverkuil@xs4all.nl> - 2016-08-02 09:40 +0200
        Re: [PATCH v7 1/2] [media] atmel-isc: add the Image Sensor Controller  code "Wu, Songjun" <Songjun.Wu@microchip.com> - 2016-08-02 10:00 +0200

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