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dmaengine: sh: rz-dmac: Save the start LM descriptor

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Save the start LM descriptor to avoid starting from the beginning of the
channel's LM descriptor list in rz_dmac_calculate_residue_bytes_in_vd().
This avoids unnecessary iterations.

Tested-by: John Madieu <john.madieu.xa@bp.renesas.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Tested-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Link: https://patch.msgid.link/20260526084710.3491480-7-claudiu.beznea@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Claudiu Beznea
2026-05-26 11:46:58 +03:00
committed by Vinod Koul
parent 32a69f1487
commit e21aa306e8
1 changed files with 8 additions and 3 deletions
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11
drivers/dma/sh/rz-dmac.c
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@@ -58,6 +58,7 @@ struct rz_dmac_desc {
/* For slave sg */
struct scatterlist *sg;
unsigned int sgcount;
struct rz_lmdesc *start_lmdesc;
};
#define to_rz_dmac_desc(d) container_of(d, struct rz_dmac_desc, vd)
@@ -343,6 +344,8 @@ static void rz_dmac_prepare_desc_for_memcpy(struct rz_dmac_chan *channel)
struct rz_dmac_desc *d = channel->desc;
u32 chcfg = CHCFG_MEM_COPY;
d->start_lmdesc = lmdesc;
/* prepare descriptor */
lmdesc->sa = d->src;
lmdesc->da = d->dest;
@@ -377,6 +380,7 @@ static void rz_dmac_prepare_descs_for_slave_sg(struct rz_dmac_chan *channel)
}
lmdesc = channel->lmdesc.tail;
d->start_lmdesc = lmdesc;
for (i = 0, sg = sgl; i < sg_len; i++, sg = sg_next(sg)) {
if (d->direction == DMA_DEV_TO_MEM) {
@@ -693,9 +697,10 @@ rz_dmac_get_next_lmdesc(struct rz_lmdesc *base, struct rz_lmdesc *lmdesc)
return next;
}
static u32 rz_dmac_calculate_residue_bytes_in_vd(struct rz_dmac_chan *channel, u32 crla)
static u32 rz_dmac_calculate_residue_bytes_in_vd(struct rz_dmac_chan *channel,
struct rz_dmac_desc *desc, u32 crla)
{
struct rz_lmdesc *lmdesc = channel->lmdesc.head;
struct rz_lmdesc *lmdesc = desc->start_lmdesc;
struct dma_chan *chan = &channel->vc.chan;
struct rz_dmac *dmac = to_rz_dmac(chan->device);
u32 residue = 0, i = 0;
@@ -794,7 +799,7 @@ static u32 rz_dmac_chan_get_residue(struct rz_dmac_chan *channel,
* Calculate number of bytes transferred in processing virtual descriptor.
* One virtual descriptor can have many lmdesc.
*/
return crtb + rz_dmac_calculate_residue_bytes_in_vd(channel, crla);
return crtb + rz_dmac_calculate_residue_bytes_in_vd(channel, current_desc, crla);
}
static enum dma_status rz_dmac_tx_status(struct dma_chan *chan,