diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2014-04-28 14:49:43 +0400 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2014-04-30 09:04:39 +0400 |
| commit | cdae05a0f0f7d15837dfd6f4200e8caea03c9cbf (patch) | |
| tree | 9513241fb0020ad9cbd0b2e2fa36f707e09b864b | |
| parent | c2da2340e5818aa72b2e847f1f24b036742ea5c7 (diff) | |
| download | linux-cdae05a0f0f7d15837dfd6f4200e8caea03c9cbf.tar.xz | |
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>
| -rw-r--r-- | arch/arm/common/edma.c | 24 | ||||
| -rw-r--r-- | include/linux/platform_data/edma.h | 2 |
2 files changed, 10 insertions, 16 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 diff --git a/include/linux/platform_data/edma.h b/include/linux/platform_data/edma.h index 923f8a3e4ce0..12f134b1493c 100644 --- a/include/linux/platform_data/edma.h +++ b/include/linux/platform_data/edma.h @@ -130,7 +130,7 @@ void edma_set_src(unsigned slot, dma_addr_t src_port, enum address_mode mode, enum fifo_width); void edma_set_dest(unsigned slot, dma_addr_t dest_port, enum address_mode mode, enum fifo_width); -void edma_get_position(unsigned slot, dma_addr_t *src, dma_addr_t *dst); +dma_addr_t edma_get_position(unsigned slot, bool dst); void edma_set_src_index(unsigned slot, s16 src_bidx, s16 src_cidx); void edma_set_dest_index(unsigned slot, s16 dest_bidx, s16 dest_cidx); void edma_set_transfer_params(unsigned slot, u16 acnt, u16 bcnt, u16 ccnt, |