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Commit cdae05a0 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Vinod Koul
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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: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarSekhar Nori <nsekhar@ti.com>
Signed-off-by: default avatarJoel Fernandes <joelf@ti.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent c2da2340

arch/arm/common/edma.c

+9 −15
Original line number Diff line number Diff line
@@ -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

include/linux/platform_data/edma.h

+1 −1
Original line number Diff line number Diff line
@@ -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,