Re: [PATCH] 2.6 ide-cd DMA ripping

[Sean Neakums <sneakums@zork.net>]

Jens Axboe <axboe@suse.de> writes:

> On Sat, Mar 06 2004, Sean Neakums wrote:
>> Jens Axboe <axboe@suse.de> writes:
>> 
>> > Hi,
>> >
>> > 2.6 still uses PIO for CDROMREADAUDIO cdda ripping, which is less than
>> > optimal of course... This patch uses the block layer infrastructure to
>> > enable zero copy DMA ripping through CDROMREADAUDIO.
>> >
>> > I'd appreciate people giving this a test spin. Patch is against
>> > 2.6.4-rc1 (well current BK, actually).
>> 
>> Applied successfully to 2.6.4-rc1-mm2, and it works great.  For some
>> reason, on two different machines, ripping with cdparanoia used to
>> somehow crowd out the serial port, but now everything just works.
>
> cd ripping was highly cpu intensive when it ran in pio, so it's very
> likely that this screwed up your serial port communication. It doesn't
> matter with the patch, but had you used hdparm -u1 on your cd device
> on an unpatched kernel, you would have had better luck.

I had a look, just for pig iron, and hdparm -u on one of the machines
reports that it is already enabled.  That machine is SMP with two
1.13GHz PIIIs.  I can't check the other machine as the drive in
question is no longer functional.