summaryrefslogtreecommitdiff
path: root/arch/arm/common
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@linutronix.de>2014-04-28 10:49:43 +0000
committerVinod Koul <vinod.koul@intel.com>2014-04-30 10:34:39 +0530
commitcdae05a0f0f7d15837dfd6f4200e8caea03c9cbf (patch)
tree9513241fb0020ad9cbd0b2e2fa36f707e09b864b /arch/arm/common
parentc2da2340e5818aa72b2e847f1f24b036742ea5c7 (diff)
dmaengine: edma: Make reading the position of active channels work
As Joel pointed out, edma_read_position() uses memcpy_fromio() to read the parameter ram. That's not synchronized with the internal update as it does a byte by byte copy. We need to do a 32bit read to get a consistent value. Further reading destination and source is pointless. In DEV_TO_MEM transfers we are only interested in the destination, in MEM_TO_DEV we care about the source. In MEM_TO_MEM it really does not matter which one you read. Simple solution: Remove the pointers, select dest/source via a bool and return the read value. Remove the export of this function while at it. The only potential user is the dmaengine and that's always builtin. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Sekhar Nori <nsekhar@ti.com> Signed-off-by: Joel Fernandes <joelf@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'arch/arm/common')
-rw-r--r--arch/arm/common/edma.c24
1 files changed, 9 insertions, 15 deletions
diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
index 0b37f7734d0f..25fa735abc6c 100644
--- a/arch/arm/common/edma.c
+++ b/arch/arm/common/edma.c
@@ -994,29 +994,23 @@ void edma_set_dest(unsigned slot, dma_addr_t dest_port,
EXPORT_SYMBOL(edma_set_dest);
/**
- * edma_get_position - returns the current transfer points
+ * edma_get_position - returns the current transfer point
* @slot: parameter RAM slot being examined
- * @src: pointer to source port position
- * @dst: pointer to destination port position
+ * @dst: true selects the dest position, false the source
*
- * Returns current source and destination addresses for a particular
- * parameter RAM slot. Its channel should not be active when this is called.
+ * Returns the position of the current active slot
*/
-void edma_get_position(unsigned slot, dma_addr_t *src, dma_addr_t *dst)
+dma_addr_t edma_get_position(unsigned slot, bool dst)
{
- struct edmacc_param temp;
- unsigned ctlr;
+ u32 offs, ctlr = EDMA_CTLR(slot);
- ctlr = EDMA_CTLR(slot);
slot = EDMA_CHAN_SLOT(slot);
- edma_read_slot(EDMA_CTLR_CHAN(ctlr, slot), &temp);
- if (src != NULL)
- *src = temp.src;
- if (dst != NULL)
- *dst = temp.dst;
+ offs = PARM_OFFSET(slot);
+ offs += dst ? PARM_DST : PARM_SRC;
+
+ return edma_read(ctlr, offs);
}
-EXPORT_SYMBOL(edma_get_position);
/**
* edma_set_src_index - configure DMA source address indexing