Subject: Re: Kernel Gurus: Module insertion deadlock? [Was: SCSI system freeze w/2.4.18]

From: Michel Dänzer <[email-masked]>
Date: 08 Apr 2002 00:32:29 +0200

On Sun, 2002-04-07 at 16:33, Albrecht Dre? wrote:
>
> I played a little more with this, and got the following picture:
>
> * scsi cd support built into the kernel: the access works without a cd in
>    the drive
>
> * scsi cd support built as module
>    - do a "modprobe sr_mod" (which inserts sr_mod.o and cdrom.o): access
>      works like support built fixed into the kernel;
>    - remove sr_mod (cdrom.o may still be loaded): access leads to the hang as
>      described.
>
> So I think there is some kind of deadlock between dd and the module
> insertion (which includes a disk access to read/load the module). As I do
> not see this on an iMac with a ide cd drive, it might be a problem either in
> sr_mod or in the scsi stuff. However, the iMac has two separate ide busses
> for the cd and the disk, so the hang might be "same bus" related.

Indeed, I've experienced the same problem on a Cube where both HD and CD-ROM
are on the first IDE bus. Used to work before around 2.4.10, don't remember
exactly.

--
Earthling Michel Dänzer (MrCooper)/ Debian GNU/Linux (powerpc) developer
XFree86 and DRI project member   /  CS student, Free Software enthusiast

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