Bug 80129 - Kernel does not support DMA with my drive/motherboard
Summary: Kernel does not support DMA with my drive/motherboard
Alias: None
Product: Red Hat Linux
Classification: Retired
Component: kernel
Version: 8.0
Hardware: i386
OS: Linux
Target Milestone: ---
Assignee: Arjan van de Ven
QA Contact: Brian Brock
Depends On:
TreeView+ depends on / blocked
Reported: 2002-12-20 10:17 UTC by John Barnes
Modified: 2007-04-18 16:49 UTC (History)
1 user (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2003-06-05 13:17:14 UTC

Attachments (Terms of Use)
dmesg (7.01 KB, text/plain)
2002-12-20 10:47 UTC, John Barnes
no flags Details

Description John Barnes 2002-12-20 10:17:27 UTC
Description of problem:
Kernel fails to activate DMA on DVD drive

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1.Create /etc/sysconfig/harddiskhdc and edit to enable and set dma on DVD drive:
2. Reboot PC
3.See failure in /var/log/messages
Dec 20 09:29:09 Titanic hdparm:  HDIO_SET_DMA failed: Operation not permitted
Dec 20 09:29:09 Titanic hdparm:  setting using_dma to 1 (on)
Dec 20 09:29:09 Titanic rc.sysinit: Setting hard drive parameters for hdc: 
Dec 20 09:29:09 Titanic hdparm:  using_dma    =  0 (off)

Actual results:
hdparm always fials to set dma on hdc

Expected results:
dma should be settable. This is needed for acceptable DVD playback.

Additional info:
See attachment.

Comment 1 Arjan van de Ven 2002-12-20 10:29:06 UTC
From the release notes:

     o DMA is disabled on CD-ROM drives in this release in a different but
       more reliable way than previously. If you are sure that your CD-ROM
       drive is capable of IDE DMA, place the following line in the
       /etc/modules.conf file:

       options ide-cd dma=1

Comment 2 John Barnes 2002-12-20 10:47:03 UTC
Created attachment 88834 [details]

Comment 3 John Barnes 2002-12-20 11:10:35 UTC
Thanks for your very quick response!

"options ide-cd dma=1" in /etc/modules.conf works fine.

Where should I have been looking to find this out for myself?

Comment 4 Michael Lee Yohe 2002-12-20 15:20:42 UTC
Quoting Arjan - "From the release notes:"

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