[lkml]   [2007]   [Aug]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 2.6.23] ibmebus: Prevent bus_id collisions
Hi Joachim-

Joachim Fenkes wrote:
> Nathan Lynch <> wrote on 29.08.2007 20:12:32:
> > Will anything break?
> Nope. Userspace programs should not depend on ibmebus' way of naming the
> devices; especially since some overly long loc_codes tended to be
> truncated and thus rendered useless. I have tested IBM's DLPAR tools
> against the changed kernel, and they didn't break.


> > Also, I dislike this approach of duplicating the firmware device tree
> > path in sysfs.
> Why? Any specific reasons for your dislike?

struct device's bus_id field is but 20 bytes in size. Too close for

> > Are GX/ibmebus devices guaranteed to be children of
> > the same node in the OF device tree? If so, their unit addresses will
> > be unique, and therefore suitable values for bus_id. I believe this
> > is what the powerpc vio bus code does.
> While there's no such guarantee (as in "officially signed document"), yes,
> I expect future GX devices to also appear beneath the OFDT root node. For
> the existing devices, the unit addresses are already part of the device
> name, so I save the need to use sprintf() again. Plus, I rather like using
> the full_name since it also contains a descriptive name as opposed to
> being just nondescript numbers, helping the layman (ie user) to make sense
> out of a dev_id.

Okay, but your layman isn't supposed to be relying on any
user-friendly properties of the name :) Hope he doesn't work on a
distro installer.

Anyway, if you're still confident in this approach, I relent. :)
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2007-08-30 19:59    [W:0.035 / U:4.676 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site