Kernel Question

[Matt Zimmerman]

On Wed, Nov 24, 2004 at 10:04:49PM +0000, Jon Dixon wrote:

> Since using Hoary, I noticed that the DMA for my DVD/CD-RW was not 
> enabled by default.
> 
> Editing /etc/hdparm.conf to enable the DMA results in a message stating 
> that /dev/hdc doesn't exit, yet it obviously does.

Perhaps it doesn't exist until later in the boot process in your case?

> The I recalled a setting in the kernel config, so I took a look and found:
> 
> CONFIG_IDEDMA_ONLYDISK=y
> 
> As I didn't need to play with DMA in Warty, is this something that was 
> introduced?

Yes.  Too many CD-ROM devices simply fail to work correctly when DMA is
enabled, and this causes many users to be unable to even install Ubuntu, so
it is disabled by default.

-- 
 - mdz