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

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.