Hi all!
I recently noticed that my newly compiled kernel 2.4.21 with support for this chipset compiled into the kernel did not set automatically the UDMA 5 transfer mode to my primary and secondary IDE disks! As you can see under my name I use RH 9, whose kernel (2.4.20-20.9) neither sets the UDMA transfer mode... Now doiong some research onthe subject I came across some refferences to this chipset on the Kernel mailing list, and there (as of 2001) they said that SiS chipsets did not support two devices of different UDMA modes on the same IDE channel... Also there was a patch to address this (which by this moment in time should be merged into the kernel driver, right?)
The problems is that I cannot set the dma argument of hdparm to the devices because I'd get this error message:
Code:
/dev/hda:
setting using_dma to 1 (on)
HDIO_SET_DMA failed: Operation not permitted
using_dma = 0 (off)
I think this is of interest: I have a Western Digital 40 Gb ATA-100/66 drive set as the primary drive and an old Seagate 8.6 Gb ATA-33 as my secondary (slave) drive... could this problem be because of this ATA mixup? or simply the driver does not support two types of transfer rate on the same channel?
