SCSI- unexpected disconnect with kernel-2.6.13-r6

SCSI- unexpected disconnect with kernel-2.6.13-r6

[mikep]

I am using a LSIU160/Symbios 53c1010 Ultra3 scsi adapter and it works at 
full speed (75 MB/sec) with kernel-2.6.12. And dmesg shows:

kernel:  target0:0:0: Beginning Domain Validation
kernel:  target0:0:0: asynchronous.
kernel: WIDTH IS 1
kernel:  target0:0:0: wide asynchronous.
kernel:  target0:0:0: FAST-80 WIDE SCSI 160.0 MB/s DT (12.5 ns, offset 62)
kernel:  target0:0:0: Ending Domain Validation
kernel: sym1: <1010-33> rev 0x1 at pci 0000:01:07.1 irq 11
kernel: sym1: Symbios NVRAM, ID 7, Fast-80, SE, parity checking
kernel: sym1: open drain IRQ line driver
kernel: sym1: using LOAD/STORE-based firmware.
kernel: sym1: handling phase mismatch from SCRIPTS.
kernel: sym1: SCSI BUS has been reset.
kernel: scsi1 : sym-2.2.0
kernel: libata version 1.11 loaded.

With kernel-2.6.13-r6 the speed drops back to 2.70 MB/sec because of
validation failure and dmesg shows:

kernel:  target0:0:0: Beginning Domain Validation
kernel:  target0:0:0: asynchronous.
kernel:  target0:0:0: wide asynchronous.
kernel:  target0:0:0: FAST-80 WIDE SCSI 160.0 MB/s DT IU QAS (
kernel: sym0: unexpected disconnect
kernel:  target0:0:0: Write Buffer failure 700ff
kernel:  target0:0:0: Domain Validation Disabing Information units
kernel:  0:0:0:0: phase change 6-7 11@3fb3c3a8 resid=10.
kernel:  target0:0:0: asynchronous.
kernel: sym0: unexpected disconnect
target0:0:0: Write Buffer failure 700ff
target0:0:0: Domain Validation detected failure, dropping back
kernel:  target0:0:0: asynchronous.
target0:0:0: Ending Domain Validation
kernel: sym1: <1010-33> rev 0x1 at pci 0000:01:07.1 irq 11
kernel: sym1: Symbios NVRAM, ID 7, Fast-80, SE, parity checkingkernel: 
sym1:
 open drain IRQ line driver, using on-chip SRAM
kernel: sym1: using LOAD/STORE-based firmware.
kernel: sym1: handling phase mismatch from SCRIPTS.
kernel: sym1: SCSI BUS has been reset.
kernel: scsi1 : sym-2.2.1
kernel: libata version 1.11 loaded.

The kernel config has:

CONFIG_SCSI_SYM53C8XX_2=y
CONFIG_SCSI_SYM53C8XX_DMA_ADDRESSING_MODE=1
CONFIG_SCSI_SYM53C8XX_DEFAULT_TAGS=16
CONFIG_SCSI_SYM53C8XX_MAX_TAGS=64
# CONFIG_SCSI_SYM53C8XX_IOMAPPED is not set