[PATCH] PIIX: remove check for broken MW DMA mode 0
There's no need to check in piix_config_drive_for_dma() for broken MW DMA
mode 0 as this mode is not supported by the driver (it sets
hwif->mwdma_mask to 0x6), and hence can't be selected by ide_dma_speed().
(Alan sayeth "Probably right but if not you've got a subtle corruptor. Should
at least stick a BUG_ON mode 0 setting right close when the mode is set.")
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/ide/pci/piix.c b/drivers/ide/pci/piix.c
index b1e9a8e..8ecd2d6 100644
--- a/drivers/ide/pci/piix.c
+++ b/drivers/ide/pci/piix.c
@@ -353,33 +353,6 @@
}
/**
- * piix_faulty_dma0 - check for DMA0 errata
- * @hwif: IDE interface to check
- *
- * If an ICH/ICH0/ICH2 interface is is operating in multi-word
- * DMA mode with 600nS cycle time the IDE PIO prefetch buffer will
- * inadvertently provide an extra piece of secondary data to the primary
- * device resulting in data corruption.
- *
- * With such a device this test function returns true. This allows
- * our tuning code to follow Intel recommendations and use PIO on
- * such devices.
- */
-
-static int piix_faulty_dma0(ide_hwif_t *hwif)
-{
- switch(hwif->pci_dev->device)
- {
- case PCI_DEVICE_ID_INTEL_82801AA_1: /* ICH */
- case PCI_DEVICE_ID_INTEL_82801AB_1: /* ICH0 */
- case PCI_DEVICE_ID_INTEL_82801BA_8: /* ICH2 */
- case PCI_DEVICE_ID_INTEL_82801BA_9: /* ICH2 */
- return 1;
- }
- return 0;
-}
-
-/**
* piix_config_drive_for_dma - configure drive for DMA
* @drive: IDE drive to configure
*
@@ -391,10 +364,6 @@
static int piix_config_drive_for_dma (ide_drive_t *drive)
{
u8 speed = ide_dma_speed(drive, piix_ratemask(drive));
-
- /* Some ICH devices cannot support DMA mode 0 */
- if(speed == XFER_MW_DMA_0 && piix_faulty_dma0(HWIF(drive)))
- speed = 0;
/* If no DMA speed was available or the chipset has DMA bugs
then disable DMA and use PIO */
