Re: [PATCH v8 2/4] fpga manager: add sysfs interface document

[Pantelis Antoniou]

Hi Pavel,

> On Jan 13, 2015, at 09:28 , Pavel Machek <pavel@xxxxxxx> wrote:
> 
> Hi!
> 
>>>>>>>>>> +What:		/sys/class/fpga_manager/<fpga>/firmware
>>>>>>>>>> +Date:		October 2014
>>>>>>>>>> +KernelVersion:	3.18
>>>>>>>>>> +Contact:	Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx>
>>>>>>>>>> +Description:	Name of the FPGA image file to load using firmware
>>>>>>>>>> class.
>>>>>>>>> 
>>>>>>>>> This one is ugly: it unneccessarily passes firmware name through the
>>>>>>>>> kernel. Just make interface and code simpler by always passing
>>>>>>>>> "socfpga-fpga-image" or something like that.
> ...
> 
>>> What is cumbersome about symlink? Why is "fake" symlink in sysfs better?
>>> 
>>>> Previous uses of the firmware layer has been to use it to load once after
>>>> bootup; this is different since some use cases will want to switch out
>>>> the FPGA image.  If someone wants there to be only one FPGA image on
>>>> the FGPA forever, they will probably not be using this framework; their
>>>> FPGA will probably be loaded before Linux boots up.
>>> 
>>> Why? I have just one image on the fpga, and would prefer to load it
>>> from Linux.
>> 
>> Pavel: These patches target staging and sysfs interface doesn't need to be stable
>> at this time. I would prefer to add these patches to staging for 3.20
>> and feel free to send the patch which fix this.
> 
> Interesting way to address patch review. "We'll merge it, and you can
> fix it up later".
> 
>> With your code will be exactly clear how you want to use it and we can
>> talk about it.
> 
> I'm pretty sure Alan knows what I want at this point, he just does not
> want to do it.
> 
> For the record, I want to drop "firmware" file, use fixed firmware
> name, and deal with multiple firmwares in userspace (using symlink or
> udev magic).
> 

Thatâs completely bogus. Using a fixed firmware file does not respond to
real world usage, and there are no words to describe the hacks using
symlinks and udev in an embedded product.

> I believe this is simplest solution, should be adequate, and is
> certainly less ugly than implementing fake symlink in
> /sys/.../firmware. And I have yet to hear what is wrong with that
> suggestion.
> 

Everything.

> Thanks,									

Regards

â Pantelis

> 									Pavel
> -- 
> (english) http://www.livejournal.com/~pavelmachek
> (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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