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

Pavel Machek
2015-01-10T15:11:23Z

On Sat 2015-01-10 10:10:51, Pantelis Antoniou wrote:
> Hi Pavel,
>
> > On Jan 9, 2015, at 22:56 , Pavel Machek <pavel@denx.de> wrote:
> >
> > On Fri 2015-01-09 13:14:24, atull wrote:
> >> On Wed, 7 Jan 2015, Pavel Machek wrote:
> >>
> >>> On Tue 2015-01-06 14:13:37, atull@opensource.altera.com wrote:
> >>>> +
> >>>> +What: /sys/class/fpga_manager/<fpga>/firmware
> >>>> +Date: October 2014
> >>>> +KernelVersion: 3.18
> >>>> +Contact: Alan Tull <atull@opensource.altera.com>
> >>>> +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.
> >>>
> >>> Thanks,
> >>> Pavel
> >>
> >> Hi Pavel,
> >>
> >> It might be ugly. It's not unnecessary. Some uses of FPGAs involve
> >> switching out the FPGA images dynamically under control of the userspace.
> >
> > Then configure udev to load right firmware for you, or ln -s
> > image-i-want-now socfpga-fpga-image to select the one to read…?
> >
>
> Who said that udev is going to be available in the kind of system this is going to end in?

Noone.

> Doing ln -s tricks to load a different image? Really?

But if you don't have udev, you can do ln -s. It is better than
open-coding symlink functionality into
/sys/class/fpga_manager/<fpga>/firmware ... cause that's what this is.

Actually, clean implementation of "firmware" would be symlink in
sysfs; but I'd say that would be overdoing it.

> I say the interface is fine as it is.

I say it is not.
Pavel
--
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