Subject: Problems with LCD panel & SCSI support with Linux 2.4.24-pre2 on Cobalt Qube II

From: Stuart Longland <[email-masked]>
Date: Mon, 02 Feb 2004 00:01:10 +1000

Hi All,
	Just the other day, I dragged out the old Gateway Microserver I have
here (a rebadged Cobalt Qube II) with the idea of setting it up as a
fileserver.

	I opened the box and dropped in an Advansys PCI SCSI card (I don't
recall the exact model) into the PCI slot, with the intent of hooking up
external SCSI drives.  I also replaced the HDD with a 40GB IBM Deskstar
I had sitting around.  On loading Debian Woody, I discover that there is
no SCSI support in the kernel, so I set about building one.

	Managed to cross compile 2.4.18 with the media patches, etc -- All
seemed to work, apart from SCSI.  modprobe advansys would complain that
the card was not present.  I also experienced hard lockups when I tried
dumping some large files to it over the LAN.

	Upgraded it to Linux 2.4.24-pre2 (CVS checkout from linux-mips done 6th
January, 2004) -- This seems to have corrected the hard lockups I had
previously, however, the SCSI card still doesn't work and now the LCD
panel on the back no-longer functions.

	I have uploaded what information I have (including output from
logfiles, lspci output, modprobe output, my toolchain versions, the
kernel config used, etc) to
http://www.longlandclan.hopto.org/~stuartl/mipsel-errors/.

	The toolchain was created on a i686-pc-linux-gnu host using the
crossdev.sh script on Gentoo Linux.  The kernel used was patched using
patches from http://people.debian.org/~pm/mips-cobalt/kernel/

	Is there anything I might have missed in trying to set this up?  I'm
fairly new to the MIPS architecture, this is the first time I managed to
get a custom MIPS kernel to boot correctly in a usable manner.  I've
noticed comments that the Cobalt support is suffering some "bit rot" and
hence, it has been quite shakey lately (well, for me anyway), however
I'd like to help out with ironing out these problems if possible.

Thanks,
- --
+-------------------------------------------------------------+
| Stuart Longland           stuartl at longlandclan.hopto.org |
| Brisbane Mesh Node: 719             http://stuartl.cjb.net/ |
| I haven't lost my mind - it's backed up on a tape somewhere |
| Atomic Linux Project    <--->    http://atomicl.berlios.de/ |
+-------------------------------------------------------------+

---

From: Karsten Merker <[email-masked]>
Date: Sun, 1 Feb 2004 15:54:48 +0100

> here (a rebadged Cobalt Qube II) with the idea of setting it up as a
[snip]
> panel on the back no-longer functions.

The device id for the LCD panel has changed in newer kernel versions;
the minor device id seems to be selected dynamically now:

static struct miscdevice lcd_dev = {
        MISC_DYNAMIC_MINOR,
        "lcd",
        &lcd_fops
};

HTH,
Karsten
-- 
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---

From: Stuart Longland <[email-masked]>
Date: Mon, 02 Feb 2004 05:34:30 +1000

Karsten Merker wrote:
| On Mon, Feb 02, 2004 at 12:01:10AM +1000, Stuart Longland wrote:
|
|
|>	Just the other day, I dragged out the old Gateway Microserver I have
|>here (a rebadged Cobalt Qube II) with the idea of setting it up as a
|>fileserver.
|
| [snip]
|
|>January, 2004) -- This seems to have corrected the hard lockups I had
|>previously, however, the SCSI card still doesn't work and now the LCD
|>panel on the back no-longer functions.
|
|
| The device id for the LCD panel has changed in newer kernel versions;
| the minor device id seems to be selected dynamically now:
|
| static struct miscdevice lcd_dev = {
|         MISC_DYNAMIC_MINOR,
|         "lcd",
|         &lcd_fops
| };
|
| HTH,
| Karsten
Hi,
	Thanks for that, this fixes the LCD problem, it's working fine now.  If
it's more dynamic, it looks like using devfs might be a better option --
although I'm trying to avoid enabling stuff that enlarges my kernel (I'm
at 600kB now).  At the moment, I'll see about putting a hack in the
scripts to recreate /dev/lcd at boot.

	Now to nail the problem with SCSI.

- --

---

From: Ralf Baechle <[email-masked]>
Date: Mon, 2 Feb 2004 21:48:01 +0100

On Mon, Feb 02, 2004 at 05:34:30AM +1000, Stuart Longland wrote:

> at 600kB now).

Devfs is not going to be the solution, that much is clear.  It's
deprecated in 2.6 and in general enjoys the positive reputation of ebola
in most of the kernel community.  For 2.4 /proc/misc allows you to get
away without devfs, something that'll also work with 2.6.  In a more
general context it looks like udev is going to be the official successor
of devfs.

> At the moment, I'll see about putting a hack in the scripts to recreate
> /dev/lcd at boot.

  Ralf