cdwriter /dev/hdc question

cdwriter /dev/hdc question

[Gene Heskett]

Greetings;

Running 2.6.2 atm, but for quite a while in the 2.6.x series I've had 
a line in /var/log/messages immediately after the dmesg dump 
indicating that dma was being disabled for /dev/hdc.
>From /var/log/dmesg:
---
VP_IDE: VIA vt8233 (rev 00) IDE UDMA100 controller on pci0000:00:11.1
    ide0: BM-DMA at 0xd800-0xd807, BIOS settings: hda:DMA, hdb:DMA
    ide1: BM-DMA at 0xd808-0xd80f, BIOS settings: hdc:DMA, hdd:DMA
[...]
hdc: CREATIVE CD-RW RW1210E, ATAPI CD/DVD-ROM drive
[...]
hdc: ATAPI 32X CD-ROM CD-R/RW drive, 2048kB Cache, DMA
Uniform CD-ROM driver Revision: 3.20
[...]
---
>From /var/log/messages, immediately after the dmesg dump:
---
Feb  4 21:30:47 coyote kernel: hdc: DMA disabled
---
However, I put an hdparm line at the bottom of rc.local that turns it 
back on and it works great, yet to see an error while burning.

So why is the kernel turning it off in the first place?

-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
99.22% setiathome rank, not too shabby for a WV hillbilly
Yahoo.com attornies please note, additions to this message
by Gene Heskett are:
Copyright 2004 by Maurice Eugene Heskett, all rights reserved.

Re: cdwriter /dev/hdc question

[John Bradford]

> So why is the kernel turning it off in the first place?

I think the error message is bogus, and that DMA is actually silently
re-enabled shortly afterwards, but I could be wrong.

John.

Re: cdwriter /dev/hdc question

[Bill Davidsen]

Gene Heskett wrote:
> Greetings;
> 
> Running 2.6.2 atm, but for quite a while in the 2.6.x series I've had 
> a line in /var/log/messages immediately after the dmesg dump 
> indicating that dma was being disabled for /dev/hdc.

I think this is bogus, in that it is silently enabled again. Ask hdparm!

I thought that message was either going to go away or be paired with a 
similar "I didn't mean it" message if the drive is reenabled, but I 
can't quickly find the discussion.

-- 
bill davidsen <davidsen@tmr.com>
   CTO TMR Associates, Inc
   Doing interesting things with small computers since 1979

Re: cdwriter /dev/hdc question

[Gene Heskett]

On Friday 06 February 2004 14:06, Bill Davidsen wrote:
>Gene Heskett wrote:
>> Greetings;
>>
>> Running 2.6.2 atm, but for quite a while in the 2.6.x series I've
>> had a line in /var/log/messages immediately after the dmesg dump
>> indicating that dma was being disabled for /dev/hdc.
>
>I think this is bogus, in that it is silently enabled again. Ask
> hdparm!
>
>I thought that message was either going to go away or be paired with
> a similar "I didn't mean it" message if the drive is reenabled, but
> I can't quickly find the discussion.

I did, its off before I turn it back on.  Silly Q:  If there is a 
readable data disk in the drive, would it still shut it off?  I'll 
check that at the next reboot.

-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
99.22% setiathome rank, not too shabby for a WV hillbilly
Yahoo.com attornies please note, additions to this message
by Gene Heskett are:
Copyright 2004 by Maurice Eugene Heskett, all rights reserved.