low performance trying pata_sis

There is a wrong order to initialize the drivers. The IDE-platform driver was initialized before pata_sis.
So the generic platform driver is driving the IDE controller instead of pata_sis.
kernel 2.6.19

.config
# CONFIG_BLK_DEV_SIS5513 is not set
CONFIG_ATA=y
CONFIG_PATA_SIS=y

dmesg
...
libata version 2.00 loaded.
...
Uniform Multi-Platform E-IDE driver Revision: 7.00alpha2
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx Probing IDE interface ide0...
hda: SAMSUNG SP1614N, ATA DISK drive
Probing IDE interface ide1...
...
pata_sis 0000:00:02.5: version 0.4.4
ata: 0x1F0 IDE port busy
ata: conflict with ide0
ata: 0x170 IDE port busy
ata: conflict with ide1
pata_sis: probe of 0000:00:02.5 failed with error -16

regards
Uwe Koziolek

I would suggest not trying to use both together - there isn't an easy way to sort that out because the generic driver in libata will grab devices before legacy drivers/ide if it is the other way around.

At least the current way around you get the old drivers by default.