Red Hat Bugzilla – Bug 80129
Kernel does not support DMA with my drive/motherboard
Last modified: 2007-04-18 12:49:11 EDT
Description of problem:
Kernel fails to activate DMA on DVD drive
Version-Release number of selected component (if applicable):
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)
hdparm always fials to set dma on hdc
dma should be settable. This is needed for acceptable DVD playback.
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
options ide-cd dma=1
Created attachment 88834 [details]
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?
Quoting Arjan - "From the release notes:"