Re: [Ksummit-discuss] [MAINTAINERS SUMMIT] Moving debugfs file systems into sysfs

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, Oct 03, 2018 at 07:32:33AM -0700, Greg Kroah-Hartman wrote:
> On Wed, Oct 03, 2018 at 03:44:37PM +0200, Jiri Kosina wrote:
> > On Wed, 3 Oct 2018, Greg Kroah-Hartman wrote:
> > 
> > > > Not really. We need those configs to be enabled to be able to troubleshoot
> > > > customer's problems - e.g., asking customer to enable some trace points or
> > > > show some stats from debugfs is pretty common...
> > > 
> > > trace points should not be in debugfs.  And what stats are in debugfs
> > > that are not availble in other tools?  If you rely on them, shouldn't we
> > > move them to a "stable" location so that they can always be accessed?
> > 
> > So I for example quite often make use of the HID debugfs entries both for 
> > reading the descriptor, and also for analyzing the parsed events (which 
> > appear there as well).
> 
> for descriptors, both usb and pci expose them through other means that
> are always present, perhaps you want to do the same thing for hid?
> 
> > Surely it can be moved whereever else (where?), but it seems to fit to 
> > debugfs (it's used solely to debug dysfunctional devices / linux with 
> > those devices), and provides exactly the data you need from the owner of 
> > the system to provide in order to be able to debug remotely.
> 
> hidfs might be needed to match usbfs :)

Why not put the raw descriptors in sysfs?  That's what pci and usb do,
there's no reason you can't do the same here.  You already have a sysfs
device.  Oh wait, you do, 'report_descriptor' right?  Why do you also
need it in debugfs?

thanks,

greg k-h