I'm trying to debug a strange problem on an IBM xSeries 206m where I installed a Debian Testing with a self-compiled Linux kernel 2.6.15. I have two SATA disks (Hitachi Deskstart HDS728080PLA380) 80 Gb, atatched to the ICH7 controller: 0000:00:1f.1 IDE interface: Intel Corporation 82801G (ICH7 Family) IDE Controller (rev 01) 0000:00:1f.2 IDE interface: Intel Corporation 82801GB/GR/GH (ICH7 Family) Serial ATA Storage Controllers cc=IDE (rev 01) Sometimes the kernel at boot time does not detect the second hard disk, as in this case: libata version 1.20 loaded. ata_piix 0000:00:1f.2: version 1.05 ACPI: PCI Interrupt 0000:00:1f.2[B] -> GSI 19 (level, low) -> IRQ 225 PCI: Setting latency timer of device 0000:00:1f.2 to 64 ata1: SATA max UDMA/133 cmd 0x30C8 ctl 0x30BE bmdma 0x3090 irq 225 ata2: SATA max UDMA/133 cmd 0x30C0 ctl 0x30BA bmdma 0x3098 irq 225 ata1: dev 0 cfg 49:2f00 82:346b 83:7fe9 84:4773 85:3469 86:3c01 87:4763 88:207f ata1: dev 0 ATA-7, max UDMA/133, 156312576 sectors: LBA48 ata1: dev 0 configured for UDMA/133 scsi0 : ata_piix ata2: SATA port has no device. scsi1 : ata_piix Vendor: ATA Model: HDS728080PLA380 Rev: PF2O Type: Direct-Access ANSI SCSI revision: 05 SCSI device sda: 156312576 512-byte hdwr sectors (80032 MB) SCSI device sda: drive cache: write back SCSI device sda: 156312576 512-byte hdwr sectors (80032 MB) SCSI device sda: drive cache: write back sda: sda1 sda2 < sda5 sda6 sda7 > sd 0:0:0:0: Attached scsi disk sda Strange enough, the bug seems to appear only if ata_piix is compiled staically into the kernel. If I use a kernel with ata_piix compiled as a module, both disks are always detected (see below the log). I tried to modify - into the ata_piix.c - the function piix_sata_phy_reset(): I repeated the piix_sata_probe() call up to 100 times if it fails, with an udelay(10) between. No luck: the "SATA port has no device" message sometimes appears. Any idea on how solve or debug this problem? Thanks. This is a log where both disks are detected: ata_piix 0000:00:1f.2: version 1.05 ACPI: PCI Interrupt 0000:00:1f.2[B] -> GSI 19 (level, low) -> IRQ 50 PCI: Setting latency timer of device 0000:00:1f.2 to 64 ata1: SATA max UDMA/133 cmd 0x30C8 ctl 0x30BE bmdma 0x3090 irq 50 ata2: SATA max UDMA/133 cmd 0x30C0 ctl 0x30BA bmdma 0x3098 irq 50 hda: ATAPI 48X CD-ROM drive, 128kB Cache, UDMA(33) Uniform CD-ROM driver Revision: 3.20 ata1: dev 0 cfg 49:2f00 82:346b 83:7fe9 84:4773 85:3469 86:3c01 87:4763 88:207f ata1: dev 0 ATA-7, max UDMA/133, 156312576 sectors: LBA48 ata1: dev 0 configured for UDMA/133 scsi0 : ata_piix ata2: dev 0 cfg 49:2f00 82:346b 83:7fe9 84:4773 85:3469 86:3c01 87:4763 88:207f ata2: dev 0 ATA-7, max UDMA/133, 156312576 sectors: LBA48 ata2: dev 0 configured for UDMA/133 scsi1 : ata_piix Vendor: ATA Model: HDS728080PLA380 Rev: PF2O Type: Direct-Access ANSI SCSI revision: 05 Vendor: ATA Model: HDS728080PLA380 Rev: PF2O Type: Direct-Access ANSI SCSI revision: 05 SCSI device sda: 156312576 512-byte hdwr sectors (80032 MB) SCSI device sda: drive cache: write back SCSI device sda: 156312576 512-byte hdwr sectors (80032 MB) SCSI device sda: drive cache: write back sda: sda1 sda2 < sda5 sda6 sda7 > sd 0:0:0:0: Attached scsi disk sda SCSI device sdb: 156312576 512-byte hdwr sectors (80032 MB) SCSI device sdb: drive cache: write back SCSI device sdb: 156312576 512-byte hdwr sectors (80032 MB) SCSI device sdb: drive cache: write back sdb: sdb1 sdb2 < sdb5 sdb6 sdb7 > sd 1:0:0:0: Attached scsi disk sdb -- Niccolo Rigacci Firenze - Italy Iraq, missione di pace: 38475 morti - www.iraqbodycount.net - : send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html