I recently compiled gentoo-sources-2.6.23-r3 and subsequently vanilla 2.6.23.12 , but could not get hdparm v 7.7 (or earlier) to set my it8212f controlled raid array to use dma. >From past experience, I have learned that my raid 1 array (using the it8212f raid controller present on my Gigabyte motherboard ) will not function properly unless it is set to use dma with hdparm. As a result, I execute hdparm -d1 /dev/hde in both the Gentoo boot and ordinary run levels. The system has worked fine with multiple 2.6.x kernels. The last kernel that I have successfully used is 2.6.20-gentoo-r7 (gentoo-sources). I have checked linux kernel archives several times and have posted this problem on gentoo forums, but have not been able to find similar reports. Perhaps related, but I doubt it, are boot messages that I initially received about disabling speeds > udma 33 due to failure to detect proper cabling on the host side of several ide interfaces (more details unfortunately vague). My cabling is definitely proper. I haven't noted the cabling messages with recent boot attempts with the problem kernels and I think (not 100% sure) they were abolished by using the "OBSOLETE" lilo boot loader append commands "ide0=ata66, ide2=ata66" I compiled the kernel with these config parameters: CONFIG_IDE=y CONFIG_BLK_DEV_IDE=y # # Please see Documentation/ide.txt for help/info on IDE drives # # CONFIG_BLK_DEV_IDE_SATA is not set # CONFIG_BLK_DEV_HD_IDE is not set CONFIG_BLK_DEV_IDEDISK=y CONFIG_IDEDISK_MULTI_MODE=y CONFIG_BLK_DEV_IDECD=y # CONFIG_BLK_DEV_IDETAPE is not set # CONFIG_BLK_DEV_IDEFLOPPY is not set # CONFIG_BLK_DEV_IDESCSI is not set # CONFIG_IDE_TASK_IOCTL is not set CONFIG_IDE_PROC_FS=y # # IDE chipset support/bugfixes # CONFIG_IDE_GENERIC=y # CONFIG_BLK_DEV_CMD640 is not set CONFIG_BLK_DEV_IDEPCI=y CONFIG_IDEPCI_SHARE_IRQ=y CONFIG_IDEPCI_PCIBUS_ORDER=y # CONFIG_BLK_DEV_OFFBOARD is not set CONFIG_BLK_DEV_GENERIC=y # CONFIG_BLK_DEV_OPTI621 is not set # CONFIG_BLK_DEV_RZ1000 is not set CONFIG_BLK_DEV_IDEDMA_PCI=y # CONFIG_BLK_DEV_IDEDMA_FORCED is not set # CONFIG_IDEDMA_ONLYDISK is not set # CONFIG_BLK_DEV_AEC62XX is not set # CONFIG_BLK_DEV_ALI15X3 is not set # CONFIG_BLK_DEV_AMD74XX is not set # CONFIG_BLK_DEV_ATIIXP is not set # CONFIG_BLK_DEV_CMD64X is not set # CONFIG_BLK_DEV_TRIFLEX is not set # CONFIG_BLK_DEV_CY82C693 is not set # CONFIG_BLK_DEV_CS5520 is not set # CONFIG_BLK_DEV_CS5530 is not set # CONFIG_BLK_DEV_CS5535 is not set # CONFIG_BLK_DEV_HPT34X is not set # CONFIG_BLK_DEV_HPT366 is not set # CONFIG_BLK_DEV_JMICRON is not set # CONFIG_BLK_DEV_SC1200 is not set CONFIG_BLK_DEV_PIIX=y # CONFIG_BLK_DEV_IT8213 is not set CONFIG_BLK_DEV_IT821X=y # CONFIG_BLK_DEV_NS87415 is not set # CONFIG_BLK_DEV_PDC202XX_OLD is not set # CONFIG_BLK_DEV_PDC202XX_NEW is not set # CONFIG_BLK_DEV_SVWKS is not set # CONFIG_BLK_DEV_SIIMAGE is not set # CONFIG_BLK_DEV_SIS5513 is not set # CONFIG_BLK_DEV_SLC90E66 is not set # CONFIG_BLK_DEV_TRM290 is not set # CONFIG_BLK_DEV_VIA82CXXX is not set # CONFIG_BLK_DEV_TC86C001 is not set # CONFIG_IDE_ARM is not set CONFIG_BLK_DEV_IDEDMA=y # CONFIG_IDEDMA_IVB is not set # CONFIG_BLK_DEV_HD is not set These are corresponding boot messages from vanilla 2.6.23.12: Kernel command line: BOOT_IMAGE=vanilla2.6.23 ro root=307 ide0=ata66 ide2=ata66 ide_setup: ide2=ata66 -- OBSOLETE OPTION, WILL BE REMOVED SOON! IT8212: IDE controller at PCI slot 0000:03:0c.0 IT8212: chipset revision 17 it821x: controller in smart mode. IT8212: 100% native mode on irq 21 ide2: BM-DMA at 0xb800-0xb807, BIOS settings: hde:DMA, hdf:pio ide3: BM-DMA at 0xb808-0xb80f, BIOS settings: hdg:pio, hdh:pio Probing IDE interface ide2... hde: Integrated Technology Express Inc, ATA DISK drive hde: IT8212 RAID 1 volume. hde: selected mode 0x0 ide2 at 0xa810-0xa817,0xac02 on irq 21 Probing IDE interface ide3... Probing IDE interface ide3... Probing IDE interface ide4... Probing IDE interface ide5... hde: max request size: 128KiB hde: 312581806 sectors (160041 MB), CHS=19457/255/63 hde: cache flushes not supported hde: hde1 hde: selected mode 0x0 EXT3 FS on hde1, internal journal hde: selected mode 0x0 Messages from hdparm after booting complete: hdparm -V : hdparm v7.7 hdparm /dev/hde: /dev/hde: multcount = 0 (off) IO_support = 0 (default 16-bit) unmaskirq = 0 (off) using_dma = 0 (off) keepsettings = 0 (off) readonly = 0 (off) readahead = 256 (on) geometry = 19457/255/63, sectors = 312581806, start = 0 hdparm -d1 /dev/hde: /dev/hde: setting using_dma to 1 (on) HDIO_SET_DMA failed: Input/output error using_dma = 0 (off) - To unsubscribe from this list: 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