2020-02-09 16:42:29

by Dmitry Osipenko

Subject: [PATCH v8 19/19] dmaengine: tegra-apb: Improve error message about DMA underflow

Technically it is possible that DMA could be misconfigured in a way that
cyclic DMA transfer is processed slower than it takes to complete the
cycle and in this case the DMA is getting aborted with a not very
informative message about the problem, let's improve it.

Suggested-by: Jon Hunter <[email protected]>
Signed-off-by: Dmitry Osipenko <[email protected]>
---
drivers/dma/tegra20-apb-dma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
index 3e0373b89195..1a9b37c102ba 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -566,7 +566,7 @@ static bool handle_continuous_head_request(struct tegra_dma_channel *tdc,
if (!hsgreq->configured) {
tegra_dma_stop(tdc);
pm_runtime_put(tdc->tdma->dev);
- dev_err(tdc2dev(tdc), "Error in DMA transfer, aborting DMA\n");
+ dev_err(tdc2dev(tdc), "DMA transfer underflow, aborting DMA\n");
tegra_dma_abort_all(tdc);
return false;
}
--
2.24.0

2020-02-14 14:16:50

by Jon Hunter

Subject: Re: [PATCH v8 19/19] dmaengine: tegra-apb: Improve error message about DMA underflow

On 09/02/2020 16:33, Dmitry Osipenko wrote:
> Technically it is possible that DMA could be misconfigured in a way that
> cyclic DMA transfer is processed slower than it takes to complete the
> cycle and in this case the DMA is getting aborted with a not very
> informative message about the problem, let's improve it.
>
> Suggested-by: Jon Hunter <[email protected]>
> Signed-off-by: Dmitry Osipenko <[email protected]>
> ---
> drivers/dma/tegra20-apb-dma.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
> index 3e0373b89195..1a9b37c102ba 100644
> --- a/drivers/dma/tegra20-apb-dma.c
> +++ b/drivers/dma/tegra20-apb-dma.c
> @@ -566,7 +566,7 @@ static bool handle_continuous_head_request(struct tegra_dma_channel *tdc,
> if (!hsgreq->configured) {
> tegra_dma_stop(tdc);
> pm_runtime_put(tdc->tdma->dev);
> - dev_err(tdc2dev(tdc), "Error in DMA transfer, aborting DMA\n");
> + dev_err(tdc2dev(tdc), "DMA transfer underflow, aborting DMA\n");
> tegra_dma_abort_all(tdc);
> return false;
> }
>

Acked-by: Jon Hunter <[email protected]>

Thanks!
Jon

--
nvpublic