1 files changed, 14 insertions, 13 deletions

diff --git a/drivers/dma/mediatek/mtk-uart-apdma.c b/drivers/dma/mediatek/mtk-uart-apdma.c
index 27c07350971d..375e7e647df6 100644
--- a/drivers/dma/mediatek/mtk-uart-apdma.c
+++ b/drivers/dma/mediatek/mtk-uart-apdma.c
@@ -131,10 +131,7 @@ static unsigned int mtk_uart_apdma_read(struct mtk_chan *c, unsigned int reg)
 
 static void mtk_uart_apdma_desc_free(struct virt_dma_desc *vd)
 {
-	struct dma_chan *chan = vd->tx.chan;
-	struct mtk_chan *c = to_mtk_uart_apdma_chan(chan);
-
-	kfree(c->desc);
+	kfree(container_of(vd, struct mtk_uart_apdma_desc, vd));
 }
 
 static void mtk_uart_apdma_start_tx(struct mtk_chan *c)
@@ -207,14 +204,9 @@ static void mtk_uart_apdma_start_rx(struct mtk_chan *c)
 
 static void mtk_uart_apdma_tx_handler(struct mtk_chan *c)
 {
-	struct mtk_uart_apdma_desc *d = c->desc;
-
 	mtk_uart_apdma_write(c, VFF_INT_FLAG, VFF_TX_INT_CLR_B);
 	mtk_uart_apdma_write(c, VFF_INT_EN, VFF_INT_EN_CLR_B);
 	mtk_uart_apdma_write(c, VFF_EN, VFF_EN_CLR_B);
-
-	list_del(&d->vd.node);
-	vchan_cookie_complete(&d->vd);
 }
 
 static void mtk_uart_apdma_rx_handler(struct mtk_chan *c)
@@ -245,9 +237,17 @@ static void mtk_uart_apdma_rx_handler(struct mtk_chan *c)
 
 	c->rx_status = d->avail_len - cnt;
 	mtk_uart_apdma_write(c, VFF_RPT, wg);
+}
 
-	list_del(&d->vd.node);
-	vchan_cookie_complete(&d->vd);
+static void mtk_uart_apdma_chan_complete_handler(struct mtk_chan *c)
+{
+	struct mtk_uart_apdma_desc *d = c->desc;
+
+	if (d) {
+		list_del(&d->vd.node);
+		vchan_cookie_complete(&d->vd);
+		c->desc = NULL;
+	}
 }
 
 static irqreturn_t mtk_uart_apdma_irq_handler(int irq, void *dev_id)
@@ -261,6 +261,7 @@ static irqreturn_t mtk_uart_apdma_irq_handler(int irq, void *dev_id)
 		mtk_uart_apdma_rx_handler(c);
 	else if (c->dir == DMA_MEM_TO_DEV)
 		mtk_uart_apdma_tx_handler(c);
+	mtk_uart_apdma_chan_complete_handler(c);
 	spin_unlock_irqrestore(&c->vc.lock, flags);
 
 	return IRQ_HANDLED;
@@ -348,7 +349,7 @@ static struct dma_async_tx_descriptor *mtk_uart_apdma_prep_slave_sg
 		return NULL;
 
 	/* Now allocate and setup the descriptor */
-	d = kzalloc(sizeof(*d), GFP_ATOMIC);
+	d = kzalloc(sizeof(*d), GFP_NOWAIT);
 	if (!d)
 		return NULL;
 
@@ -366,7 +367,7 @@ static void mtk_uart_apdma_issue_pending(struct dma_chan *chan)
 	unsigned long flags;
 
 	spin_lock_irqsave(&c->vc.lock, flags);
-	if (vchan_issue_pending(&c->vc)) {
+	if (vchan_issue_pending(&c->vc) && !c->desc) {
 		vd = vchan_next_desc(&c->vc);
 		c->desc = to_mtk_uart_apdma_desc(&vd->tx);