Hello, I am getting following error when trying to set DMA transfer mode as UDMA2 on latest DaVinci (DM6467) git kernel using hdparm (9.27 or older): # ./hdparm -d1 -Xudma2 /dev/hda /dev/hda:hda: UDMA/66 mode selected setting using_dma to 1 (on) hda: UDMA/66 mode selected setting xfermode to 66 (UltraDMA mode2) HDIO_DRIVE_CMD(setxfermode) failed: Invalid argument using_dma = 1 (on) It seems DMA mode setting other than the default mode returns this error. That is, if I use "-Xudma4" in above command it returns success as UDMA4 is the default mode on DM6467. I made following change which allows hdparm to set any supported DMA mode. Can anyone confirm if this is a hdparm compatibility (incorrect use of ioctl?) or the patch below indeed fixes the issue? diff --git a/drivers/ide/ide-ioctls.c b/drivers/ide/ide-ioctls.c index d3440b5..6e7ae2b 100644 --- a/drivers/ide/ide-ioctls.c +++ b/drivers/ide/ide-ioctls.c @@ -162,7 +162,7 @@ static int ide_cmd_ioctl(ide_drive_t *drive, unsigned long arg) if (tf->command == ATA_CMD_SET_FEATURES && tf->feature == SETFEATURES_XFER && tf->nsect >= XFER_SW_DMA_0) { - xfer_rate = ide_find_dma_mode(drive, XFER_UDMA_6); + xfer_rate = ide_find_dma_mode(drive, tf->nsect); if (xfer_rate != tf->nsect) { err = -EINVAL; goto abort; Thanks. - Hemant -- 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