cvs commit: src/sys/dev/usb usb.c

Bernd Walter ticso at
Sat Mar 26 03:32:21 PST 2005

On Fri, Mar 25, 2005 at 05:42:02PM -0700, M. Warner Losh wrote:
> In message: <424473BB.4010607 at>
>             Maxim Sobolev <sobomax at> writes:
> : This is still suboptimal, since even after this change when ehci is 
> : enabled some (if not most) USB devices are detected after system goes 
> : into milti-user mode. Obviously, this makes it impossible to mount root 
> : fs off the USB HDD/FDD/CD. The simplest way to solve this problem is to 
> : add some sufficiently long and configurable delay before mounting root 
> : fs (similar to one used by the SCSI) when ehci is enabled to let those 
> : devices to be detected and attached.
> /me notes that usb subsystem will know when it is done enumerating
> devices.  cardbus has a similar issue...

It doesn't seem to work:
Trying to mount root from ufs:/dev/ad0a
umass1: Generic USB Storage Device, rev 1.10/1.00, addr 6
umass1: SCSI over Bulk-Only; quirks = 0x0000
umass1:2:1:-1: Attached to scbus2
da4 at umass-sim1 bus 1 target 0 lun 0
da4: <IC USB Storage-CFC 301b> Removable Direct Access SCSI-0 device 
da4: 1.000MB/s transfers
da4: Attempt to query device size failed: NOT READY, Medium not present

And this is not just CAM that is too late - it is the whole umass
instance that gets attached after root mount.

B.Walter                   BWCT      
bernd at                                  info at

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