> That doesn't seem right, after my experiences with SuSE. (I'l still in > the process of my first Gentoo install...) > > I have a combo CD-RW/DVD drive that uses SCSI emulation (under SuSE). I > discovered the need to turn DMA on when DVDs/VCDs wouldn't play back > correctly. (Jumpy playback...) I turned it on with their gui, and > everything worked correctly.
SuSE does it by having both the /dev/hdx and /dev/sr? devices in /dev When you turned on DMA, it used the /dev/hdx device to turn on DMA. You can do this in Gentoo manually, by creating the device manually and then using hdparm with the created device. I haven't tested the interaction with devfs, (i.e. does the created device stick around after a reboot) but I did verify that it works. What you need to do is execute one of the following commands based upon which device is your SCSI emulated CD-ROM. (The device numbers can be found /usr/src/linux/Documentation/devices.txt) /dev/hda: mknod /dev/hda b 3 0 /dev/hdb: mknod /dev/hdb b 3 64 /dev/hdc: mknod /dev/hdc b 22 0 /dev/hdd: mknod /dev/hdd b 22 64 After that you should be able to use hdparm normally. Here is the output from my system. (I have /dev/hdc, SCSI emulated) garath root # hdparm /dev/hdc /dev/hdc: No such file or directory garath root # ls -l /dev/hdc ls: /dev/hdc: No such file or directory garath root # mknod /dev/hdc b 22 0 garath root # ls -l /dev/hdc brw-r--r-- 1 root root 22, 0 Jan 22 19:43 /dev/hdc garath root # hdparm /dev/hdc /dev/hdc: HDIO_GET_MULTCOUNT failed: Invalid argument IO_support = 0 (default 16-bit) unmaskirq = 0 (off) using_dma = 1 (on) keepsettings = 0 (off) readonly = 0 (off) BLKRAGET failed: Invalid argument HDIO_GETGEO failed: Invalid argument garath root # hdparm -d0 /dev/hdc /dev/hdc: setting using_dma to 0 (off) using_dma = 0 (off) garath root # hdparm -d1 /dev/hdc /dev/hdc: setting using_dma to 1 (on) using_dma = 1 (on) Regards, Paul -- My Gentoo stuff: http://varnerfamily.org/pvarner/gentoo -- [EMAIL PROTECTED] mailing list
