Currently, ide_cmd_ioctl when invoked for setting DMA transfer mode calls ide_find_dma_mode with requested mode as XFER_UDMA_6. This prevents setting DMA mode to any other value than the default (maximum) supported by the device (or UDMA6, if supported) irrespective of the actual requested transfer mode and returns error. For example, setting mode to UDMA2 using hdparm, where UDMA4 is the default transfer mode gives following error: # ./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) This patch fixes the issue. Signed-off-by: Hemant Pedanekar <hemantp@xxxxxx> Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx> Acked-by: Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx> --- drivers/ide/ide-ioctls.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) 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; -- 1.6.2.4 -- 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