2022-06-29 04:02:28

by Jie Hai

Subject: [PATCH v2 2/7] dmaengine: hisilicon: Fix CQ head update

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")
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Jie Hai <[email protected]>
---
drivers/dma/hisi_dma.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/hisi_dma.c b/drivers/dma/hisi_dma.c
index 98bc488893cc..7609e6e7eb37 100644
--- a/drivers/dma/hisi_dma.c
+++ b/drivers/dma/hisi_dma.c
@@ -436,12 +436,12 @@ 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(hdma_dev->base,
+ HISI_DMA_CQ_HEAD_PTR, chan->qp_num,
+ chan->cq_head);
if (FIELD_GET(STATUS_MASK, cqe->w0) == STATUS_SUCC) {
- chan->cq_head = (chan->cq_head + 1) %
- hdma_dev->chan_depth;
- hisi_dma_chan_write(hdma_dev->base,
- HISI_DMA_CQ_HEAD_PTR, chan->qp_num,
- chan->cq_head);
vchan_cookie_complete(&desc->vd);
} else {
dev_err(&hdma_dev->pdev->dev, "task error!\n");
--
2.33.0

2022-07-21 14:10:23

by Vinod Koul

Subject: Re: [PATCH v2 2/7] dmaengine: hisilicon: Fix CQ head update

On 29-06-22, 11:55, 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")
> Reported-by: kernel test robot <[email protected]>
> Signed-off-by: Jie Hai <[email protected]>
> ---
> drivers/dma/hisi_dma.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/dma/hisi_dma.c b/drivers/dma/hisi_dma.c
> index 98bc488893cc..7609e6e7eb37 100644
> --- a/drivers/dma/hisi_dma.c
> +++ b/drivers/dma/hisi_dma.c
> @@ -436,12 +436,12 @@ 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;

This can look better with single line

> + hisi_dma_chan_write(hdma_dev->base,
> + HISI_DMA_CQ_HEAD_PTR, chan->qp_num,
> + chan->cq_head);

maybe two lines?

> if (FIELD_GET(STATUS_MASK, cqe->w0) == STATUS_SUCC) {
> - chan->cq_head = (chan->cq_head + 1) %
> - hdma_dev->chan_depth;
> - hisi_dma_chan_write(hdma_dev->base,
> - HISI_DMA_CQ_HEAD_PTR, chan->qp_num,
> - chan->cq_head);
> vchan_cookie_complete(&desc->vd);
> } else {
> dev_err(&hdma_dev->pdev->dev, "task error!\n");
> --
> 2.33.0

--
~Vinod

2022-07-26 01:41:31

by Jie Hai

Subject: Re: [PATCH v2 2/7] dmaengine: hisilicon: Fix CQ head update

On 2022/7/21 21:27, Vinod Koul wrote:
> On 29-06-22, 11:55, 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")
>> Reported-by: kernel test robot <[email protected]>
>> Signed-off-by: Jie Hai <[email protected]>
>> ---
>> drivers/dma/hisi_dma.c | 10 +++++-----
>> 1 file changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/dma/hisi_dma.c b/drivers/dma/hisi_dma.c
>> index 98bc488893cc..7609e6e7eb37 100644
>> --- a/drivers/dma/hisi_dma.c
>> +++ b/drivers/dma/hisi_dma.c
>> @@ -436,12 +436,12 @@ 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;
>
> This can look better with single line
>
Thanks for your reviewing.
These issues have been fixed in V3.
>> + hisi_dma_chan_write(hdma_dev->base,
>> + HISI_DMA_CQ_HEAD_PTR, chan->qp_num,
>> + chan->cq_head);
>
> maybe two lines?
>
>> if (FIELD_GET(STATUS_MASK, cqe->w0) == STATUS_SUCC) {
>> - chan->cq_head = (chan->cq_head + 1) %
>> - hdma_dev->chan_depth;
>> - hisi_dma_chan_write(hdma_dev->base,
>> - HISI_DMA_CQ_HEAD_PTR, chan->qp_num,
>> - chan->cq_head);
>> vchan_cookie_complete(&desc->vd);
>> } else {
>> dev_err(&hdma_dev->pdev->dev, "task error!\n");
>> --
>> 2.33.0
>