lkml.org 
[lkml]   [2006]   [Feb]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Device enumeration (was Re: CD writing in future Linux (stirring up a hornets' nest))
Olivier Galibert wrote:
[]
> 4- sysfs has all the information you need, just read it
[]
> Answer 4 would be very nice if it was correct. sysfs is pretty much
> mandatory at that point, and modulo some fixable incompleteness
> provides all the capability information and model names and everything
> needed to find the useful devices. What it does not provide is the
> mapping between a device as found in sysfs, and a device node you can
> open to talk to the device. You get the major/minor, which allows you
> to create a temporary device node iff you're root. Or you can scan
> all the nodes in /dev to find the one to open, which is kinda
> ridiculous and inefficient. Or you have to go back to udev/hal to ask
> for the sysfs node/device node path mapping, and then why use sysfs in
> the first place.

That's exactly the point why I always wanted to have automatic minimal-devfs-
alike in kernel, similar to ndevfs but complete: so that kernel names of
defices are *always* present in /dev, regardless of the presense of udev or
something else. All the rest - udev, device permissions, "alternative"
names (like /dev/cdrom etc) can be built on top of that "kernel naming scheme",
but the key point is that we *always* have a device in /dev/ named exactly
the same as kernel "thinks" of it - so eg, /proc/partitions, dmesg output,
sysfs scanning etc etc will produce real and useful results.

But oh.. Am I starting new [n]devfs flamewar?

/mjt
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-02-14 12:55    [W:0.222 / U:0.572 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site