2019-06-28 12:10:34

by Sricharan R

Subject: [PATCH] dmaengine: qcom: bam_dma: Fix completed descriptors count

One space is left unused in circular FIFO to differentiate
'full' and 'empty' cases. So take that in to account while
counting for the descriptors completed.

Fixes the issue reported here,
https://lkml.org/lkml/2019/6/18/669

Cc: [email protected]
Reported-by: Srinivas Kandagatla <[email protected]>
Signed-off-by: Sricharan R <[email protected]>
---
drivers/dma/qcom/bam_dma.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
index 4b43844..8e90a40 100644
--- a/drivers/dma/qcom/bam_dma.c
+++ b/drivers/dma/qcom/bam_dma.c
@@ -799,6 +799,9 @@ static u32 process_channel_irqs(struct bam_device *bdev)
/* Number of bytes available to read */
avail = CIRC_CNT(offset, bchan->head, MAX_DESCRIPTORS + 1);

+ if (offset < bchan->head)
+ avail--;
+
list_for_each_entry_safe(async_desc, tmp,
&bchan->desc_list, desc_node) {
/* Not enough data to read */
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

2019-06-28 12:27:16

by Srinivas Kandagatla

Subject: Re: [PATCH] dmaengine: qcom: bam_dma: Fix completed descriptors count

On 28/06/2019 13:09, Sricharan R wrote:
> One space is left unused in circular FIFO to differentiate
> 'full' and 'empty' cases. So take that in to account while
> counting for the descriptors completed.
>
> Fixes the issue reported here,
> https://lkml.org/lkml/2019/6/18/669
>
> Cc: [email protected]
> Reported-by: Srinivas Kandagatla <[email protected]>
> Signed-off-by: Sricharan R <[email protected]>

Thanks for the patch, It works for me now!

Tested-by: Srinivas Kandagatla <[email protected]>

--srini

> ---
> drivers/dma/qcom/bam_dma.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
> index 4b43844..8e90a40 100644
> --- a/drivers/dma/qcom/bam_dma.c
> +++ b/drivers/dma/qcom/bam_dma.c
> @@ -799,6 +799,9 @@ static u32 process_channel_irqs(struct bam_device *bdev)
> /* Number of bytes available to read */
> avail = CIRC_CNT(offset, bchan->head, MAX_DESCRIPTORS + 1);
>
> + if (offset < bchan->head)
> + avail--;
> +
> list_for_each_entry_safe(async_desc, tmp,
> &bchan->desc_list, desc_node) {
> /* Not enough data to read */
>

2019-07-05 08:48:43

by Vinod Koul

Subject: Re: [PATCH] dmaengine: qcom: bam_dma: Fix completed descriptors count

On 28-06-19, 17:39, Sricharan R wrote:
> One space is left unused in circular FIFO to differentiate
> 'full' and 'empty' cases. So take that in to account while
> counting for the descriptors completed.
>
> Fixes the issue reported here,
> https://lkml.org/lkml/2019/6/18/669

Applied, thanks

--
~Vinod