This is a note to let you know that I've just added the patch titled
dmaengine: mediatek: do not issue a new desc if one is still current
to the 5.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dmaengine-mediatek-do-not-issue-a-new-desc-if-one-is.patch
and it can be found in the queue-5.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2ec03dbfcd2517841c9fcfeff42fbfeb35d3836d
Author: Guillaume Ranquet <granquet@xxxxxxxxxxxx>
Date: Thu May 13 21:26:41 2021 +0200
dmaengine: mediatek: do not issue a new desc if one is still current
[ Upstream commit 2537b40b0a4f61d2c83900744fe89b09076be9c6 ]
Avoid issuing a new desc if one is still being processed as this can
lead to some desc never being marked as completed.
Signed-off-by: Guillaume Ranquet <granquet@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210513192642.29446-3-granquet@xxxxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/dma/mediatek/mtk-uart-apdma.c b/drivers/dma/mediatek/mtk-uart-apdma.c
index e38b67fc0c0c..a09ab2dd3b46 100644
--- a/drivers/dma/mediatek/mtk-uart-apdma.c
+++ b/drivers/dma/mediatek/mtk-uart-apdma.c
@@ -204,14 +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)
@@ -242,9 +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)
@@ -258,6 +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;
@@ -363,7 +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);
