serial console handling changed in 2.6.16-1?

["Toni L. Harbaugh-Blackford [Contr]" <harbaugh@abcc.ncifcrf.gov>]

Hi

I am trying to figure out why the mini.iso (2.6.16-1 kernel) I tried
to install yesterday on my Xserve G5 hung.  The last log entries
printed before the hang were:

   .
   .
   .
   Dquot-cache hash table entries: 512 (order 0, 4096 bytes)
   Initializing Cryptographic API
   io scheduler noop registered
   io scheduler anticipatory registered (default)
   io scheduler deadline registered
   io scheduler cfq registered
   HVSI: registered 0 devices
   Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing disabled
   pmac_zilog: 0.6 (Benjamin Herrenschmidt <benh@kernel.crashing.org>)
   pmac_zilog: Error registering serial device, disabling pmac_zilog.
   pmac_zilog: Did another serial driver already claim the minors?
   Trying to im_free nonexistent area (d0000800820d7000)

With the last daily image (2.6.15-1 kernel), which *DOES* boot, there
is no mention of 'Trying to im_free' anything, nor is there a
pmac_zilog error.  Here is the section of the log file from the
2.6.15-1 boot, continuing past the pmac_zilog stuff:

   .
   .
   .
   Dquot-cache hash table entries: 512 (order 0, 4096 bytes)
   Initializing Cryptographic API
   io scheduler noop registered
   io scheduler anticipatory registered
   io scheduler deadline registered
   io scheduler cfq registered
   HVSI: registered 0 devices
   serial8250_init: nothing to do on PowerMac
   pmac_zilog: 0.6 (Benjamin Herrenschmidt <benh@kernel.crashing.org>)
   ttyS0 at MMIO 0x80013020 (irq = 22) is a Z85c30 ESCC - Serial port
   ttyS1 at MMIO 0x80013000 (irq = 23) is a Z85c30 ESCC - Serial port
   .
   .
   .

It seems to me that I should not be getting the pmac_zilog error about
registering the serial device.

Has something changed in the way the serial console is handled between
these two versions?

Thanks,
Toni

-------------------------------------------------------------------
Toni Harbaugh-Blackford                   harbaugh@abcc.ncifcrf.gov
System Administrator
Advanced Biomedical Computing Center (ABCC)
National Cancer Institute
Contractor - SAIC/Frederick