Hi

Ive recently installed redhat 9 (i was using redhat 8 previously) and ive encountered a problem. I was able to install redhat 9 from the iso's just fine, but now when i insert a cd the whole computer locks up. The mouse stops working, and i cant return to a command prompt by using ctrl+alt+backspace. The drive appears to keep seeking as the light remains on, and the eject button has no effect. The only way to get back control of the computer is to reset it.

The only errors i can find are in the dmesg log as follows:

hdc: CRD-8400C, ATAPI CD/DVD-ROM drive
hdc: set_drive_speed_status: status=0x51 { DriveReady SeekComplete Error }
hdc: set_drive_speed_status: error=0xb4

thanks
Simon

what does 'hdparm /dev/hdc' say?

It returns:

/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 = 1 (on)
readahead = 8 (on)
HDIO_GETGEO failed: Invalid argument

Simon

" using_dma = 1 (on)" - does ur drive and IDE interface/mobo slot support DMA?

u can try disabling dma by:

hdparm -d0 /dev/hdc

and then retry using the CDROM drive.

Great, that worked thanks.

Simon

One more thing. This worked, then i rebooted, and the dma settings had returned to there previous settings. How can i make this a permanent change of settings?

thanks
Simon

Simply edit yours
/etc/rc.d/rc.M
or
/etc/rc.d/rc.local
or.
/"your home dirictory"/.profile

and add yours hdparm configurations like
hdparm -d 0
etc..
See You !

That worked, thanks! on a more trivial note, the errors are still appearing in dmesg, which is obviously because dma is being disabled alot later in the reboot process. Is it possible to either disable those particular errors in the dmesg, or instruct linux to disable dma on hdc before it comes to generating the error.

thanks
Simon

Maybe try disabling DMA on that drive in your BIOS?
Possibly linux gets its initial settings from there, although i'm not sure...

Have fun,
nukkel

Also, set this line in /etc/modules.conf:

options ide-cd dma=0