Latest working kernel version: none
Earliest failing kernel version: 2.6.27.7
Distribution: Slackware 12.2
Hardware Environment: 

Mainboard: 939Dual-VSTA, BIOS P1.30
SATA-Controller: ULi M5289

Problem Description:

sata_uli does not detect, when a drive is plugged in or removed while the system is running. Thus manual intervention is required to add or remove a drive.

The hardware itself supports SATA hotswap (it works flawlessy with another well known operating system from Redmond using m5289.sys), so Linux should support it also.

Steps to reproduce:

Booting up without a drive connected:

sata_uli 0000:00:12.1: version 1.3
sata_uli 0000:00:12.1: PCI INT A -> GSI 19 (level, low) -> IRQ 19
scsi4 : sata_uli
scsi5 : sata_uli
ata5: SATA max UDMA/133 cmd 0xbc00 ctl 0xb480 bmdma 0xb000 irq 19
ata6: SATA max UDMA/133 cmd 0xb400 ctl 0xb080 bmdma 0xb008 irq 19

Connecting the drive, nothing happens, manual adding it to the kernel is required:

# echo 0 - 0 > /sys/class/scsi_host/host4/scan
ata5: exception Emask 0x12 SAct 0x0 SErr 0x4850400 action 0xe frozen
ata5: SError: { Proto PHYRdyChg CommWake LinkSeq DevExch }
ata5: soft resetting link
ata5: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
ata5.00: ATA-8: WDC WD5000AACS-00ZUB0, 01.01B01, max UDMA/133
ata5.00: 976773168 sectors, multi 0: LBA48 NCQ (depth 0/32)
ata5.00: configured for UDMA/133
ata5: EH complete
scsi 4:0:0:0: Direct-Access     ATA      WDC WD5000AACS-0 01.0 PQ: 0 ANSI: 5
sd 4:0:0:0: [sdb] 976773168 512-byte hardware sectors (500108 MB)
sd 4:0:0:0: [sdb] Write Protect is off
sd 4:0:0:0: [sdb] Mode Sense: 00 3a 00 00
sd 4:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
sd 4:0:0:0: [sdb] 976773168 512-byte hardware sectors (500108 MB)
sd 4:0:0:0: [sdb] Write Protect is off
sd 4:0:0:0: [sdb] Mode Sense: 00 3a 00 00
sd 4:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
 sdb: sdb1 sdb2 < sdb5 sdb6 >
sd 4:0:0:0: [sdb] Attached SCSI disk
sd 4:0:0:0: Attached scsi generic sg1 type 0

Removing the drive manually from the kernel is needed before removal:

# echo /sys/class/scsi_host/host4/device/target*/*/delete
sd 4:0:0:0: [sdb] Synchronizing SCSI cache
sd 4:0:0:0: [sdb] Stopping disk
ata5.00: disabled