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 5.10-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-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 2004c37bbd835ecfb712aa9f77187b1cc9f1e42d 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);