[PATCH] dmaengine: jz4780: Set max number of SGs per burst

[PATCH] dmaengine: jz4780: Set max number of SGs per burst

[Artur Rojek]

Total amount of SG list entries executed in a single burst is limited by
the number of available DMA descriptors.
This information is useful for device drivers utilizing this DMA engine.

Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
---
 drivers/dma/dma-jz4780.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c
index ebee94dbd630..96701dedcac8 100644
--- a/drivers/dma/dma-jz4780.c
+++ b/drivers/dma/dma-jz4780.c
@@ -915,6 +915,7 @@ static int jz4780_dma_probe(struct platform_device *pdev)
 	dd->dst_addr_widths = JZ_DMA_BUSWIDTHS;
 	dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
 	dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+	dd->max_sg_burst = JZ_DMA_MAX_DESC;
 
 	/*
 	 * Enable DMA controller, mark all channels as not programmable.
-- 
2.33.0

Re: [PATCH] dmaengine: jz4780: Set max number of SGs per burst

[Paul Cercueil]

Hi,

Le dim., août 29 2021 at 21:58:05 +0200, Artur Rojek 
<contact@artur-rojek.eu> a écrit :
> Total amount of SG list entries executed in a single burst is limited 
> by
> the number of available DMA descriptors.
> This information is useful for device drivers utilizing this DMA 
> engine.
> 
> Signed-off-by: Artur Rojek <contact@artur-rojek.eu>

Acked-by: Paul Cercueil <paul@crapouillou.net>

Cheers,
-Paul

> ---
>  drivers/dma/dma-jz4780.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c
> index ebee94dbd630..96701dedcac8 100644
> --- a/drivers/dma/dma-jz4780.c
> +++ b/drivers/dma/dma-jz4780.c
> @@ -915,6 +915,7 @@ static int jz4780_dma_probe(struct 
> platform_device *pdev)
>  	dd->dst_addr_widths = JZ_DMA_BUSWIDTHS;
>  	dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
>  	dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
> +	dd->max_sg_burst = JZ_DMA_MAX_DESC;
> 
>  	/*
>  	 * Enable DMA controller, mark all channels as not programmable.
> --
> 2.33.0
> 

Re: [PATCH] dmaengine: jz4780: Set max number of SGs per burst

[Paul Cercueil]

Hi Vinod,

Le lun., août 30 2021 at 10:48:52 +0100, Paul Cercueil 
<paul@crapouillou.net> a écrit :
> Hi,
> 
> Le dim., août 29 2021 at 21:58:05 +0200, Artur Rojek 
> <contact@artur-rojek.eu> a écrit :
>> Total amount of SG list entries executed in a single burst is 
>> limited \x7fby
>> the number of available DMA descriptors.
>> This information is useful for device drivers utilizing this DMA 
>> \x7fengine.
>> 
>> Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
> 
> Acked-by: Paul Cercueil <paul@crapouillou.net>

Feedback on this?

Cheers,
-Paul

>> ---
>>  drivers/dma/dma-jz4780.c | 1 +
>>  1 file changed, 1 insertion(+)
>> 
>> diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c
>> index ebee94dbd630..96701dedcac8 100644
>> --- a/drivers/dma/dma-jz4780.c
>> +++ b/drivers/dma/dma-jz4780.c
>> @@ -915,6 +915,7 @@ static int jz4780_dma_probe(struct 
>> \x7fplatform_device *pdev)
>>  	dd->dst_addr_widths = JZ_DMA_BUSWIDTHS;
>>  	dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
>>  	dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
>> +	dd->max_sg_burst = JZ_DMA_MAX_DESC;
>> 
>>  	/*
>>  	 * Enable DMA controller, mark all channels as not programmable.
>> --
>> 2.33.0
>> 
> 

Re: [PATCH] dmaengine: jz4780: Set max number of SGs per burst

[Vinod Koul]

On 29-08-21, 21:58, Artur Rojek wrote:
> Total amount of SG list entries executed in a single burst is limited by
> the number of available DMA descriptors.
> This information is useful for device drivers utilizing this DMA engine.

Applied, thanks

-- 
~Vinod