[PATCH 5.15 050/206] dmaengine: sh: rz-dmac: Fix rz_dmac_terminate_all()

Greg Kroah-Hartman
2026-02-04T14:54:15Z

From: Biju Das <biju.das.jz@bp.renesas.com>

commit 747213b08a1ab6a76e3e3b3e7a209cc1d402b5d0 upstream.

After audio full duplex testing, playing the recorded file contains a few
playback frames from the previous time. The rz_dmac_terminate_all() does
not reset all the hardware descriptors queued previously, leading to the
wrong descriptor being picked up during the next DMA transfer. Fix the
above issue by resetting all the descriptor headers for a channel in
rz_dmac_terminate_all() as rz_dmac_lmdesc_recycle() points to the proper
descriptor header filled by the rz_dmac_prepare_descs_for_slave_sg().

Cc: stable@kernel.org
Fixes: 5000d37042a6 ("dmaengine: sh: Add DMAC driver for RZ/G2L SoC")
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Tested-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://patch.msgid.link/20251113195052.564338-1-biju.das.jz@bp.renesas.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/dma/sh/rz-dmac.c | 5 +++++
1 file changed, 5 insertions(+)

--- a/drivers/dma/sh/rz-dmac.c
+++ b/drivers/dma/sh/rz-dmac.c
@@ -531,11 +531,16 @@ rz_dmac_prep_slave_sg(struct dma_chan *c
static int rz_dmac_terminate_all(struct dma_chan *chan)
{
struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
+ struct rz_lmdesc *lmdesc = channel->lmdesc.base;
unsigned long flags;
+ unsigned int i;
LIST_HEAD(head);

rz_dmac_disable_hw(channel);
spin_lock_irqsave(&channel->vc.lock, flags);
+ for (i = 0; i < DMAC_NR_LMDESC; i++)
+ lmdesc[i].header = 0;
+
list_splice_tail_init(&channel->ld_active, &channel->ld_free);
list_splice_tail_init(&channel->ld_queue, &channel->ld_free);
spin_unlock_irqrestore(&channel->vc.lock, flags);