Red Hat Bugzilla – Bug 155895
CONFIG_SERIAL_8250=y prevents CONFIG_SERIAL_PMACZILOG=m from working on pmac
Last modified: 2008-03-10 19:34:29 EDT
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Description of problem:
On pmac 8250 conflicts with pmac_zilog.ko, so having it built into the kernel means pmac users cannot
use their serial ports. Shouldn't the pmac default be have 8250 unused or as a module?
Looking at the current cvs, CONFIG_SERIAL_8250 is defined in configs/config-generic, which gets
combined with config-ppc-generic and config-ppc-pmac[-smp] to create kernel-2.6.11-ppc[-
smp].config. Is it possible to override the definition from config-generic in config-ppc-pmac* ?
Or is there some other way to get around the built-in 8250?
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. modprobe pmac_zilog
Actual Results: FATAL: Error inserting pmac_zilog (/lib/modules/2.6.11-1.1261_FC4smp/kernel/drivers/serial/
pmac_zilog.ko): Device or resource busy
Apr 25 09:50:18 bert kernel: pmac_zilog: 0.6 (Benjamin Herrenschmidt <email@example.com>)
Apr 25 09:50:18 bert kernel: pmac_zilog: i2c-modem detected, id: 1
Apr 25 09:50:18 bert kernel: pmac_zilog: Error registering serial device, disabling pmac_zilog.
Apr 25 09:50:18 bert kernel: pmac_zilog: Did another serial driver already claim the minors?
Expected Results: normal pmac_zilog load
pmac dual g4 450
A new kernel update has been released (Version: 2.6.18-1.2200.fc5)
based upon a new upstream kernel release.
Please retest against this new kernel, as a large number of patches
go into each upstream release, possibly including changes that
may address this problem.
This bug has been placed in NEEDINFO state.
Due to the large volume of inactive bugs in bugzilla, if this bug is
still in this state in two weeks time, it will be closed.
Should this bug still be relevant after this period, the reporter
can reopen the bug at any time. Any other users on the Cc: list
of this bug can request that the bug be reopened by adding a
comment to the bug.
In the last few updates, some users upgrading from FC4->FC5
have reported that installing a kernel update has left their
systems unbootable. If you have been affected by this problem
please check you only have one version of device-mapper & lvm2
installed. See bug 207474 for further details.
If this bug is a problem preventing you from installing the
release this version is filed against, please see bug 169613.
If this bug has been fixed, but you are now experiencing a different
problem, please file a separate bug for the new problem.
Problem still exists:
"modprobe pmac_zilog" yields
FATAL: Error inserting pmac_zilog
(/lib/modules/2.6.18-1.2207smp/kernel/drivers/serial/pmac_zilog.ko): Device or
and in /var/log/messages:
Oct 18 21:52:22 bert kernel: pmac_zilog: 0.6 (Benjamin Herrenschmidt
Oct 18 21:52:22 bert kernel: pmac_zilog: i2c-modem detected, id: 1
Oct 18 21:52:22 bert kernel: pmac_zilog: Error registering serial device,
Oct 18 21:52:22 bert kernel: pmac_zilog: Did another serial driver already claim
Problem persists in 2.6.18-1.2849.fc6smp
pmac_zilog: 0.6 (Benjamin Herrenschmidt <firstname.lastname@example.org>)
pmac_zilog: i2c-modem detected, id: 1
pmac_zilog: Error registering serial device, disabling pmac_zilog.
pmac_zilog: Did another serial driver already claim the minors?
Yeah, we need LANANA to assign device numbers for pmac_zilog rather than
continuing to abuse the device numbers which belong to 8250.
What's the maximum number of such devices which could be found in a machine?
From pmac_zilog.h: #define MAX_ZS_PORTS 4
Ok, I've mailed email@example.com to assign four minors.
After a reminder, I finally got a response. Should be fixed in the next rawhide
build (2.6.20-1.3037). Once confirmed there we'll backport the fix to FC6.
Awesome!!! Thanks, David. I will test and confirm when available.
I lied; 3038 not 3037.
Looks like your fix has gone walkabout. As of kernel version 3059, pmac_zilog
support is still borked.
Looks like it's still there to me, and seems to work on my PowerBook in the
latest kernel I tried. What's the failure mode for you? Is the module loaded?
"We" are OK now.
minicom was unable to connect to the internal modem configured to use /dev/ttyS0.
pmac_zilog kernel module is loaded, but is unused:
pmac_zilog 22300 0
Watching /var/log/messages, while reloading the module reveals the source of the
Apr 13 09:16:58 plantain kernel: pmac_zilog: 0.6 (Benjamin Herrenschmidt
Apr 13 09:16:58 plantain kernel: pmac_zilog: i2c-modem detected, id: 1
Apr 13 09:16:58 plantain kernel: ttyPZ0 at MMIO 0x80013020 (irq = 22) is a
Z85c30 ESCC - Internal modem
Apr 13 09:16:58 plantain kernel: ttyPZ1 at MMIO 0x80013000 (irq = 50) is a
Z85c30 ESCC - Serial port
==> The pmac_zlog ports are named ttyPZ0 and ttyPZ1.
reconfigure minicom to use ttyPZ0:
* the modem now responds
* kernel module is used while minicom is running:
pmac_zilog 22300 2
You can mark this bug closed and retro-fit the changes into FC6.
Thank you, David.
Closing this bug as requested in the previous comment.