Re: /sys rules Re: [RFC PATCH] fpga: Introduce new fpga subsystem

Pavel Machek
2013-09-19T22:48:25Z

On Thu 2013-09-19 07:37:15, Greg KH wrote:
> On Thu, Sep 19, 2013 at 10:20:48AM -0400, Jason Cooper wrote:
> > On Thu, Sep 19, 2013 at 04:10:46PM +0200, Michal Simek wrote:
> > > On 09/19/2013 04:06 PM, Greg KH wrote:
> > > > On Thu, Sep 19, 2013 at 02:52:37PM +0200, Pavel Machek wrote:
> > > >> On Thu 2013-09-19 13:22:00, Michal Simek wrote:
> > > >>> On 09/19/2013 01:17 PM, Pavel Machek wrote:
> > > >>
> > > >>>>> Status is just there and for my zynq devcfg driver I do export some status
> > > >>>>> bits.
> > > >>>>>
> > > >>>>> root@petalinux:~# cat /sys/class/fpga/fpga0/status
> > > >>>>> partial_bitstream_status: 0
> > > >>>>> prog_done_status: 1
> > > >>>>> dbg_lock_status: 0
> > > >>>>> seu_lock_status: 0
> > > >>>>> aes_en_lock_status: 0
> > > >>>>> aes_status: 0
> > > >>>>> seu_status: 0
> > > >>>>> spniden_status: 1
> > > >>>>> spiden_status: 1
> > > >>>>> niden_status: 1
> > > >>>>> dbgen_status: 1
> > > >>>>> dap_en_status: 7
> > > >>>>
> > > >>>> This is single file? If so, it needs to be changed. Greg is rather
> > > >>>> clear about that.
> > > >>>
> > > >>> Don't you have a link to these rules? I have seen any paragraph from Greg
> > > >>> about it but I forget where was it.
> > > >>
> > > >> "one value per file" and "there must be documentation in
> > > >> Documentation/ for each file" are the rules, iirc.
> > > >>
> > > >> There's Documentation/sysfs-rules.txt, but it does not seem too
> > > >> relevant.
> > > >
> > > > Documentation/filesystems/sysfs.txt says it. It probably should be
> > > > added to sysfs-rules.txt as well, but the odds that anyone ever reads
> > > > the documentation is so low I doubt it's even worth it.
> > > >
> > > > Also, all sysfs files have to be documented in Documentation/ABI/ which
> > > > this patch does not do :(
> > > >
> > > > And yes, multiple values in a single sysfs file is not allowed at all.
> > > >
> > >
> > > ok. I will read that. This is output from my fpga end driver - nothing
> > > what I have sent for review.
> >
> > If this is useful to you (and others), you could use debugfs for this.
> > The rules there are intentionally a lot more lax.
>
> Yes, there is only one rule in debugfs, "There is no rules".

Yeah. OTOH, depending on debugfs for normal operation would be
ugly. Don't do that (tm).
Pavel

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