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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 /include
parent20e2de4a505aa02131a95665e8920eb053fce686 (diff)
downloadop-kernel-dev-b15b3ebae102f89c25ccbcae0b2099af312f2e82.zip
op-kernel-dev-b15b3ebae102f89c25ccbcae0b2099af312f2e82.tar.gz
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 'include')
-rw-r--r--include/linux/libata.h22
1 files changed, 22 insertions, 0 deletions
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 80233fdc..225bfc5 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1429,6 +1429,28 @@ static inline unsigned long ata_deadline(unsigned long from_jiffies,
return from_jiffies + msecs_to_jiffies(timeout_msecs);
}
+/* Don't open code these in drivers as there are traps. Firstly the range may
+ change in future hardware and specs, secondly 0xFF means 'no DMA' but is
+ > UDMA_0. Dyma ddreigiau */
+
+static inline int ata_using_mwdma(struct ata_device *adev)
+{
+ if (adev->dma_mode >= XFER_MW_DMA_0 && adev->dma_mode <= XFER_MW_DMA_4)
+ return 1;
+ return 0;
+}
+
+static inline int ata_using_udma(struct ata_device *adev)
+{
+ if (adev->dma_mode >= XFER_UDMA_0 && adev->dma_mode <= XFER_UDMA_7)
+ return 1;
+ return 0;
+}
+
+static inline int ata_dma_enabled(struct ata_device *adev)
+{
+ return (adev->dma_mode == 0xFF ? 0 : 1);
+}
/**************************************************************************
* PMP - drivers/ata/libata-pmp.c
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