Re: dev_printk output

[Matthew Wilcox <matthew@wil.cx>]

On Fri, May 19, 2006 at 01:28:47PM -0700, Greg KH wrote:
> On Fri, May 19, 2006 at 02:11:42PM -0600, Matthew Wilcox wrote:
> > On Thu, May 18, 2006 at 01:09:57PM -0700, Patrick Mansfield wrote:
> > > Funky how loading sd after sg changes the output ... and using the driver
> > > name as a prefix sometimes messes this up for scsi.
> > > 
> > >  0:0:0:0: Attached scsi generic sg0 type 0
> > > sd 1:0:0:0: Attached scsi generic sg0 type 0
> > 
> > I find that a bit confusing too.  Obviously, we should distinguish
> > different kinds of bus_id from each other somehow -- but isn't the
> > obvious thing to use the bus name?  That must already be unique as sysfs
> > relies on it.  ie this patch:
> 
> Yes, not all devices are on a bus, so this will not work.  And we want
> to know the driver that controls the device too.  So how about adding
> the bus if it's not null?
> 
> Something like (untested):
> 	printk(level "%s %s %s: " format , (dev)->bus ? (dev)->bus->name : "", (dev)->driver ? (dev)->driver->name : "", (dev)->bus_id , ## arg)

Then we still get the inconsistency of device names changing as drivers
are loaded.  I think we should declare it a bug for devices to not be
on a bus.  The only example I have of devices not-on-a-bus are scsi
targets.  I would propose introducing a new scsi_target bus for them,
then removing the 'target' from the start of the bus_id.  Adding them to
the scsi bus looks like it'd be a lot of work.