FC3: DVD DMA support vs libata, a (S)ATA(PI) nightmare?

[wwp]

Hello Robin,


On Wed, 30 Nov 2005 08:15:58 -0700 Robin Laing <Robin.Laing at drdc-rddc.gc.ca> wrote:

> wwp wrote:
> > Hello all!
> > 
> > 
> > I'm unsuccessfully struggling w/ DMA support for my Dell D810's DVD drive
> > (`hdparm -d 1 /dev/hdc` fails, and I get poor performances when
> > reading/writing, it even slows down the reactivity of the system).
> > 
> > I'm running out of ideas and even of hope, since none of my attempts to
> > get DMA were successful, and reading/writing CD/DVD w/ such prehistoric
> > perfs :-).
> > 
> > I tried to customize/rebuild a 2.6.12-1.1381_FC3 kernel to get the
> > following lines in include/linux/libata.h:
> >   #define ATA_ENABLE_ATAPI
> >   #define ATA_ENABLE_PATA
> > then tried hdc=ide-scsi or hdc=scsi as boot params, loading ide-scsi
> > module thru /etc/rc.local, but nothing works. According to the variety of
> > tests I did, I get or not /dev/hdc, /dev/scd0 or /dev/sr0 (if I add the
> > device node manually), w/ various hdparm reports (read-ahead info present
> > or not) but hdparm always fails to set DMA:
> > 
> > /dev/(hdc|sr0|scd0):
> >  setting using_dma to 1 (on)
> >  HDIO_SET_DMA failed: Invalid argument
> > 
> > FYI, w/ default boot params of FC3 kernel, I get:
> > /dev/sda <- the hdd
> > /dev/hdc <- the CD/DVD drive (CD recorder)
> > 
> > If I use hdc=ide-scsi, /var/log/messages tells me:
> >   kernel: sr0: scsi3-mmc drive: 8x/24x writer cd/rw xa/form2 cdda tray
> > but I'm not that confident that ide-scsi should be used
> > since /var/log/messages tells me:
> >   ide-scsi is deprecated for cd burning! Use ide-cd and give dev=/dev/hdX
> > as device
> > 
> > Any hint would be welcome, I'm definitely lost now! :-) Can't FC3 kernels
> > (even if modified) enable DMA for such DVD drives? Should I use a vanilla
> > kernel? How to use ide-cd? Is there life on Mars, and hope for me?
> > 
> > BTW: noticed that `modprobe -r ide-scsi` simply crashes the kernel, huhu.
> > 
> > 
> > References:
> > http://cri.ch/linux/docs/sk0010.html
> > http://www.lazy8.nu/delld180/DebianLinuxOnDellLattitude810laptop.html
> > http://casa.colorado.edu/~ajsh/alienware/index.html#DVD
> > http://tkrat.org/d810/
> > http://fedora.redhat.com/docs/release-notes/fc3/x86/
> > 
> > 
> > Regards,
> > 
> 
> I have a similar issue with FC4 and my Toshiba Laptop.  In my case it 
> is related to the controller IH6 if I remember off of the top of my 
> head.  As it has been in heavy usage, I have not been able to look 
> into it much.
> 
>  From what I do remember is it has to do with two different driver 
> types and this has to be re-written into one single driver.  It may 
> not be your problem.

Well.. thanks for sharing your experience!

What I'm wondering is what I did miss or did wrong so that it doesn't work
for me, whereas some other people succeeded (three first references in my
previous email). I'm trying to understand if FC3 kernels are blocker or..  

The best for me would be if someone else is running FC3 on a Dell D810, w/ or
w/o FC3 kernel in fact.


Regards,

-- 
wwp