[PATCH v2 05/64] dmaengine: ep93xx: hook callbacks via dma_chan BH

From: Allen Pais

Date: Mon Jul 27 2026 - 16:33:27 EST


Replace the per-channel tasklet with the shared dma_chan BH helper.
The handler continues to run in softirq context while dmaengine owns
the common scheduling and teardown mechanism.

Signed-off-by: Allen Pais <allen.lkml@xxxxxxxxx>
---
drivers/dma/ep93xx_dma.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/dma/ep93xx_dma.c b/drivers/dma/ep93xx_dma.c
index 311e55a97ba9..8f5200750fe9 100644
--- a/drivers/dma/ep93xx_dma.c
+++ b/drivers/dma/ep93xx_dma.c
@@ -167,7 +167,6 @@ struct ep93xx_dma_chan_cfg {
* @dma_cfg: channel number, direction
* @irq: interrupt number of the channel
* @clk: clock used by this channel
- * @tasklet: channel specific tasklet used for callbacks
* @lock: lock protecting the fields following
* @flags: flags for the channel
* @buffer: which buffer to use next (0/1)
@@ -196,7 +195,6 @@ struct ep93xx_dma_chan {
struct ep93xx_dma_chan_cfg dma_cfg;
int irq;
struct clk *clk;
- struct tasklet_struct tasklet;
/* protects the fields following */
spinlock_t lock;
unsigned long flags;
@@ -801,9 +799,9 @@ static void ep93xx_dma_advance_work(struct ep93xx_dma_chan *edmac)
spin_unlock_irqrestore(&edmac->lock, flags);
}

-static void ep93xx_dma_tasklet(struct tasklet_struct *t)
+static void ep93xx_dma_tasklet(struct dma_chan *chan)
{
- struct ep93xx_dma_chan *edmac = from_tasklet(edmac, t, tasklet);
+ struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan);
struct ep93xx_dma_desc *desc, *d;
struct dmaengine_desc_callback cb;
LIST_HEAD(list);
@@ -858,12 +856,12 @@ static irqreturn_t ep93xx_dma_interrupt(int irq, void *dev_id)
switch (edmac->edma->hw_interrupt(edmac)) {
case INTERRUPT_DONE:
desc->complete = true;
- tasklet_schedule(&edmac->tasklet);
+ dma_chan_schedule_bh(&edmac->chan);
break;

case INTERRUPT_NEXT_BUFFER:
if (test_bit(EP93XX_DMA_IS_CYCLIC, &edmac->flags))
- tasklet_schedule(&edmac->tasklet);
+ dma_chan_schedule_bh(&edmac->chan);
break;

default:
@@ -1420,7 +1418,7 @@ static struct ep93xx_dma_engine *ep93xx_dma_of_probe(struct platform_device *pde
INIT_LIST_HEAD(&edmac->active);
INIT_LIST_HEAD(&edmac->queue);
INIT_LIST_HEAD(&edmac->free_list);
- tasklet_setup(&edmac->tasklet, ep93xx_dma_tasklet);
+ dma_chan_init_bh(&edmac->chan, ep93xx_dma_tasklet);

list_add_tail(&edmac->chan.device_node,
&dma_dev->channels);
--
2.43.0