Re: 2.4.23 : timeouts and lost interrupts using IDE-SCSI

From: Kristian Peters
Date: Thu Dec 04 2003 - 11:16:24 EST

Jimmie Mayfield <mayfield+kernel@xxxxxxxxxxxxx> schrieb:
> Since upgrading from 2.4.20 to 2.4.23, I can no longer mount my ATAPI CDROM and
> CDR/W drives using IDE-SCSI. Attempts to mount those drives result in
> lost interrupts messages:

That is normal and intended. You should see some "dma disabled" messages in your kernel-log (unless if you haven't enabled "DMA only for disks"). ATAPI/cdrom does not work reliable with DMA on 2.4. I think Andre Hedrick has switched that off after 2.4.20.
If you really want ide-scsi with dma you should try 2.6.

This is how it should like:

SCSI subsystem driver Revision: 1.00
hdb: attached ide-scsi driver.
hdb: DMA disabled <------
hdd: attached ide-scsi driver.
hdd: DMA disabled <------
scsi0 : SCSI host adapter emulation for IDE ATAPI devices
Vendor: COMPAQ Model: CD-ROM LTN485 Rev: KQA4
Type: CD-ROM ANSI SCSI revision: 02
Vendor: HP Model: CD-Writer+ 9100b Rev: 1.06
Type: CD-ROM ANSI SCSI revision: 02

So you should disable that option in your config or if you prefer using hdparm try it with "-d0 /dev/cdrom".

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