[PATCH v2 3/3] dmaengine: at_hdmac: use descriptor chaining help function

From: Nicolas Ferre
Date: Fri May 06 2011 - 12:49:51 EST


A little function helps to chain descriptors:
it is already used in cyclic dma operations, now use it in memcpy and slave_sg
preparation functions.

Signed-off-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
---
drivers/dma/at_hdmac.c | 33 +++------------------------------
1 files changed, 3 insertions(+), 30 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 5968245..2c6bc3a 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -626,16 +626,7 @@ atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,

desc->txd.cookie = 0;

- if (!first) {
- first = desc;
- } else {
- /* inform the HW lli about chaining */
- prev->lli.dscr = desc->txd.phys;
- /* insert the link descriptor to the LD ring */
- list_add_tail(&desc->desc_node,
- &first->tx_list);
- }
- prev = desc;
+ atc_desc_chain(&first, &prev, desc);
}

/* First descriptor of the chain embedds additional information */
@@ -726,16 +717,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
| len >> mem_width;
desc->lli.ctrlb = ctrlb;

- if (!first) {
- first = desc;
- } else {
- /* inform the HW lli about chaining */
- prev->lli.dscr = desc->txd.phys;
- /* insert the link descriptor to the LD ring */
- list_add_tail(&desc->desc_node,
- &first->tx_list);
- }
- prev = desc;
+ atc_desc_chain(&first, &prev, desc);
total_len += len;
}
break;
@@ -769,16 +751,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
| len >> reg_width;
desc->lli.ctrlb = ctrlb;

- if (!first) {
- first = desc;
- } else {
- /* inform the HW lli about chaining */
- prev->lli.dscr = desc->txd.phys;
- /* insert the link descriptor to the LD ring */
- list_add_tail(&desc->desc_node,
- &first->tx_list);
- }
- prev = desc;
+ atc_desc_chain(&first, &prev, desc);
total_len += len;
}
break;
--
1.7.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/