diff options
| author | Koichiro Den <den@valinux.co.jp> | 2026-08-21 02:34:36 +0900 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2026-09-09 19:06:51 +0530 |
| commit | 080b8cfa01bc86e5c601ff625a34bec30cf08156 (patch) | |
| tree | 7f5f6c42315c1f5c3c60dce4d9d174401b98346d | |
| parent | 8d249a120ce615804edab065ef4d157dbc92125f (diff) | |
| download | linux-next-080b8cfa01bc86e5c601ff625a34bec30cf08156.tar.gz linux-next-080b8cfa01bc86e5c601ff625a34bec30cf08156.zip | |
dmaengine: dw-edma: Centralize LL doorbell decisions
LL fill currently rings the doorbell every time. A running eDMA or HDMA
channel follows entries whose CB matches CCS without another kick. A
channel stopped at a CB mismatch needs one.
Move that decision to dw_edma_core_ch_maybe_doorbell(). It rings only
for a BUSY LL channel with pending entries, no EDMA_REQ_STOP or
EDMA_REQ_PAUSE. The BUSY check prevents EDMA_REQ_STOP completion from
restarting terminated work.
issue_pending() still publishes LL entries only from IDLE. A later patch
allows live appends. Non-LL channels are unchanged.
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Koichiro Den <den@valinux.co.jp>
Link: https://patch.msgid.link/20260820173439.2004068-8-den@valinux.co.jp
Signed-off-by: Vinod Koul <vkoul@kernel.org>
| -rw-r--r-- | drivers/dma/dw-edma/dw-edma-core.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c index 3c1f3f728875..5a8407ca68a2 100644 --- a/drivers/dma/dw-edma/dw-edma-core.c +++ b/drivers/dma/dw-edma/dw-edma-core.c @@ -167,8 +167,6 @@ static void dw_edma_core_ll_start(struct dw_edma_desc *desc) desc->done_burst = desc->start_burst; desc->start_burst = i; - - dw_edma_core_ch_doorbell(chan); } static void dw_edma_core_start(struct dw_edma_desc *desc) @@ -249,6 +247,16 @@ static void dw_edma_finish_termination(struct dw_edma_chan *chan) chan->status = EDMA_ST_IDLE; } +/* Must be called with vc.lock held. */ +static void dw_edma_core_ch_maybe_doorbell(struct dw_edma_chan *chan) +{ + if (chan->non_ll || chan->request != EDMA_REQ_NONE || + chan->status != EDMA_ST_BUSY || !dw_edma_ll_pending(chan)) + return; + + dw_edma_core_ch_doorbell(chan); +} + static void dw_edma_device_caps(struct dma_chan *dchan, struct dma_slave_caps *caps) { @@ -374,6 +382,7 @@ static int dw_edma_device_resume(struct dma_chan *dchan) chan->status = EDMA_ST_BUSY; if (!dw_edma_start_transfer(chan)) chan->status = EDMA_ST_IDLE; + dw_edma_core_ch_maybe_doorbell(chan); } return err; @@ -420,6 +429,7 @@ static void dw_edma_device_issue_pending(struct dma_chan *dchan) chan->status == EDMA_ST_IDLE) { chan->status = EDMA_ST_BUSY; dw_edma_start_transfer(chan); + dw_edma_core_ch_maybe_doorbell(chan); } spin_unlock_irqrestore(&chan->vc.lock, flags); } @@ -733,6 +743,8 @@ static void dw_edma_done_interrupt(struct dw_edma_chan *chan) default: break; } + dw_edma_core_ch_maybe_doorbell(chan); + spin_unlock_irqrestore(&chan->vc.lock, flags); } |