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authorAlan Cox <alan@redhat.com>2008-08-01 09:18:34 +0100
committerJeff Garzik <jgarzik@redhat.com>2008-08-22 02:27:49 -0400
commitb15b3ebae102f89c25ccbcae0b2099af312f2e82 (patch)
tree73f64d0e578d1c6bc6a3dc43f940a31f24daad8f /drivers/ata/pata_sc1200.c
parent20e2de4a505aa02131a95665e8920eb053fce686 (diff)
downloadlinux-b15b3ebae102f89c25ccbcae0b2099af312f2e82.tar.bz2
libata: Fix a large collection of DMA mode mismatches
Dave Müller sent a diff for the pata_oldpiix that highlighted a problem where a lot of the ATA drivers assume dma_mode == 0 means "no DMA" while the core code uses 0xFF. This turns out to have other consequences such as code doing >= XFER_UDMA_0 also catching 0xFF as UDMAlots. Fortunately it doesn't generally affect set_dma_mode, although some drivers call back into their own set mode code from other points. Having been through the drivers I've added helpers for using_udma/using_mwdma dma_enabled so that people don't open code ranges that may change (eg if UDMA8 appears somewhere) Thanks to David for the initial bits [and added fix for pata_oldpiix from and signed-off-by Dave Mueller <dave.mueller@gmx.ch> -jg] Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/ata/pata_sc1200.c')
-rw-r--r--drivers/ata/pata_sc1200.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/ata/pata_sc1200.c b/drivers/ata/pata_sc1200.c
index cbab397e3db7..0278fd2b8fb1 100644
--- a/drivers/ata/pata_sc1200.c
+++ b/drivers/ata/pata_sc1200.c
@@ -167,10 +167,10 @@ static unsigned int sc1200_qc_issue(struct ata_queued_cmd *qc)
struct ata_device *prev = ap->private_data;
/* See if the DMA settings could be wrong */
- if (adev->dma_mode != 0 && adev != prev && prev != NULL) {
+ if (ata_dma_enabled(adev) && adev != prev && prev != NULL) {
/* Maybe, but do the channels match MWDMA/UDMA ? */
- if ((adev->dma_mode >= XFER_UDMA_0 && prev->dma_mode < XFER_UDMA_0) ||
- (adev->dma_mode < XFER_UDMA_0 && prev->dma_mode >= XFER_UDMA_0))
+ if ((ata_using_udma(adev) && !ata_using_udma(prev)) ||
+ (ata_using_udma(prev) && !ata_using_udma(adev)))
/* Switch the mode bits */
sc1200_set_dmamode(ap, adev);
}