Re: [PATCH v2 2/2] !!! FOR TESTING ONLY !!! dmaengine: pl330: add verbose message and set NR_DEFAULT_DESC to 1

[Marek Szyprowski <m.szyprowski@samsung.com>]

Hi Alexander,

On 2017-10-04 13:37, Alexander Kochetkov wrote:
> Commit add verbose output to pl330 showing what changes introduced by
> commit 1/2 from series work as expected. You should see similar output
> running modified kernel:
>
> The patch tested on rk3188 radxdarock. Could someone else test it on
> other hardware with pl330 DMA?
>
> root@host:~# dmesg | grep pl330
> [    0.277520] dma-pl330 20018000.dma-controller: Loaded driver for PL330 DMAC-241330
> [    0.277538] dma-pl330 20018000.dma-controller: 	DBUFF-32x8bytes Num_Chans-6 Num_Peri-12 Num_Events-12
> [    0.279894] dma-pl330 20078000.dma-controller: Loaded driver for PL330 DMAC-241330
> [    0.279910] dma-pl330 20078000.dma-controller: 	DBUFF-64x8bytes Num_Chans-7 Num_Peri-20 Num_Events-14
> [    1.344804] dma-pl330 20078000.dma-controller: pl330_get_desc:2458 Allocated one more descriptor
> [    1.344832] dma-pl330 20078000.dma-controller: pl330_get_desc:2458 Allocated one more descriptor
> [    1.344853] dma-pl330 20078000.dma-controller: pl330_get_desc:2458 Allocated one more descriptor
> [    1.344873] dma-pl330 20078000.dma-controller: pl330_get_desc:2458 Allocated one more descriptor
> [    1.344893] dma-pl330 20078000.dma-controller: pl330_get_desc:2458 Allocated one more descriptor
> [    1.344912] dma-pl330 20078000.dma-controller: pl330_get_desc:2458 Allocated one more descriptor
> --- rest of similar lines omitted ---
>
> Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>

Seems to be working fine on Exynos4412 OdroidU3 board:

# dmesg | grep pl330
[    0.725608] dma-pl330 12680000.pdma: Loaded driver for PL330 DMAC-141330
[    0.725629] dma-pl330 12680000.pdma:         DBUFF-32x4bytes 
Num_Chans-8 Num_Peri-32 Num_Events-32
[    0.731338] dma-pl330 12690000.pdma: Loaded driver for PL330 DMAC-141330
[    0.731357] dma-pl330 12690000.pdma:         DBUFF-32x4bytes 
Num_Chans-8 Num_Peri-32 Num_Events-32
[    0.733097] dma-pl330 12850000.mdma: Loaded driver for PL330 DMAC-141330
[    0.733115] dma-pl330 12850000.mdma:         DBUFF-64x8bytes 
Num_Chans-8 Num_Peri-1 Num_Events-32
[   98.353073] dma-pl330 12680000.pdma: pl330_get_desc:2460 Allocated 
one more descriptor
[   98.360970] dma-pl330 12680000.pdma: pl330_get_desc:2460 Allocated 
one more descriptor
[   98.368867] dma-pl330 12680000.pdma: pl330_get_desc:2460 Allocated 
one more descriptor

> ---
>   drivers/dma/pl330.c |    5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> index deec4a4..3441c16 100644
> --- a/drivers/dma/pl330.c
> +++ b/drivers/dma/pl330.c
> @@ -266,7 +266,7 @@ enum pl330_byteswap {
>   
>   /* The number of default descriptors */
>   
> -#define NR_DEFAULT_DESC	16
> +#define NR_DEFAULT_DESC	1
>   
>   /* Delay for runtime PM autosuspend, ms */
>   #define PL330_AUTOSUSPEND_DELAY 20
> @@ -2455,6 +2455,9 @@ static struct dma_pl330_desc *pl330_get_desc(struct dma_pl330_chan *pch)
>   
>   		desc = pluck_desc(&pool, &lock);
>   		WARN_ON(!desc || !list_empty(&pool));
> +
> +		dev_err(pch->dmac->ddma.dev, "%s:%d Allocated one more descriptor\n",
> +			__func__, __LINE__);
>   	}
>   
>   	/* Initialize the descriptor */

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland