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Message-ID: <YrlKZgC999AYMvXY@matsya>
Date: Mon, 27 Jun 2022 11:42:54 +0530
From: Vinod Koul <vkoul@...nel.org>
To: Jie Hai <haijie1@...wei.com>
Cc: wangzhou1@...ilicon.com, dmaengine@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/8] dmaengine: hisilicon: Fix CQ head update
On 25-06-22, 15:44, Jie Hai wrote:
> After completion of data transfer of one or multiple descriptors,
> the completion status and the current head pointer to submission
> queue are written into the CQ and interrupt can be generated to
> inform the software. In interrupt process CQ is read and cq_head
> is updated.
>
> hisi_dma_irq updates cq_head only when the completion status is
> success. When an abnormal interrupt reports, cq_head will not update
> which will cause subsequent interrupt processes read the error CQ
> and never report the correct status.
>
> This patch updates cq_head whenever CQ is accessed.
>
> Fixes: e9f08b65250d ("dmaengine: hisilicon: Add Kunpeng DMA engine support")
>
No need for blank line
> Signed-off-by: Jie Hai <haijie1@...wei.com>
> ---
> drivers/dma/hisi_dma.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/dma/hisi_dma.c b/drivers/dma/hisi_dma.c
> index 98bc488893cc..0a0f8a4d168a 100644
> --- a/drivers/dma/hisi_dma.c
> +++ b/drivers/dma/hisi_dma.c
> @@ -436,12 +436,11 @@ static irqreturn_t hisi_dma_irq(int irq, void *data)
> desc = chan->desc;
> cqe = chan->cq + chan->cq_head;
> if (desc) {
> + chan->cq_head = (chan->cq_head + 1) %
> + hdma_dev->chan_depth;
> + hisi_dma_chan_write(q_base, HISI_DMA_Q_CQ_HEAD_PTR,
q_base?
--
~Vinod
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