Module Name:	src
Committed By:	bouyer
Date:		Wed Dec 16 13:02:04 UTC 1998

Modified Files:
	src/sys/dev/ata: ata_wdc.c atavar.h
	src/sys/dev/ic: wdc.c
	src/sys/dev/scsipi: atapi_wdc.c
Log Message:
Keep track of DMA errors, and downgrade the transert mode (UDMA ->DMA,
DMA->PIO) in case of 2 consecutive errors. Don't downgrade if the
PIO/DMA/UDMA modes were forced by a config flag.