From: Alan Cox <alan@xxxxxxxxxx>
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
Signed-off-by: Alan Cox <alan@xxxxxxxxxx>
---
drivers/ata/libata-core.c | 4 ++--
drivers/ata/pata_acpi.c | 2 +-
drivers/ata/pata_atiixp.c | 2 +-
drivers/ata/pata_cs5530.c | 6 +++---
drivers/ata/pata_sc1200.c | 6 +++---
include/linux/libata.h | 22 ++++++++++++++++++++++
6 files changed, 32 insertions(+), 10 deletions(-)
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index b4297ea..d7b6633 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -3267,7 +3267,7 @@ int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
dev->dma_mode = ata_xfer_mask2mode(dma_mask);
found = 1;
- if (dev->dma_mode != 0xff)
+ if (ata_dma_enabled(dev))
used_dma = 1;
}
if (!found)
@@ -3292,7 +3292,7 @@ int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
/* step 3: set host DMA timings */
ata_link_for_each_dev(dev, link) {
- if (!ata_dev_enabled(dev) || dev->dma_mode == 0xff)
+ if (!ata_dev_enabled(dev) || !ata_dma_enabled(dev))
continue;
dev->xfer_mode = dev->dma_mode;
diff --git a/drivers/ata/pata_acpi.c b/drivers/ata/pata_acpi.c
index c5f91e6..783e3c2 100644
--- a/drivers/ata/pata_acpi.c
+++ b/drivers/ata/pata_acpi.c
@@ -181,7 +181,7 @@ static unsigned int pacpi_qc_issue(struct ata_queued_cmd *qc)
if (adev != acpi->last) {
pacpi_set_piomode(ap, adev);
- if (adev->dma_mode)
+ if (ata_dma_enabled(adev))
pacpi_set_dmamode(ap, adev);
acpi->last = adev;
}
diff --git a/drivers/ata/pata_atiixp.c b/drivers/ata/pata_atiixp.c
index d7de7ba..e8a0d99 100644
--- a/drivers/ata/pata_atiixp.c
+++ b/drivers/ata/pata_atiixp.c
@@ -183,7 +183,7 @@ static void atiixp_bmdma_start(struct ata_queued_cmd *qc)
u16 tmp16;
pci_read_config_word(pdev, ATIIXP_IDE_UDMA_CONTROL, &tmp16);
- if (adev->dma_mode >= XFER_UDMA_0)
+ if (ata_using_udma(adev))
tmp16 |= (1 << dn);
else
tmp16 &= ~(1 << dn);
diff --git a/drivers/ata/pata_cs5530.c b/drivers/ata/pata_cs5530.c
index 744beeb..0c4b271 100644
--- a/drivers/ata/pata_cs5530.c
+++ b/drivers/ata/pata_cs5530.c
@@ -149,10 +149,10 @@ static unsigned int cs5530_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 */
cs5530_set_dmamode(ap, adev);
}
diff --git a/drivers/ata/pata_sc1200.c b/drivers/ata/pata_sc1200.c
index cbab397..0278fd2 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);
}
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 6820d6b..9bfe49e 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1427,6 +1427,28 @@ 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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