Re: [PATCH 04/14] dmaengine: dma-jz4780: Add support for the JZ4770 SoC

[Paul Cercueil]

Le lun. 9 juil. 2018 à 19:10, Vinod <vkoul@xxxxxxxxxx> a écrit :
> On 03-07-18, 14:32, Paul Cercueil wrote:
>
> >  +static inline void jz4780_dma_chan_disable(struct jz4780_dma_dev 
> > *jzdma,
> >  +	unsigned int chn)
> >  +{
> >  +	if (jzdma->version == ID_JZ4770)
> >  +		jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DCKEC, BIT(chn));
> >  +}
>
> this sounds as hardware behaviour, so why not describe as a property 
> in
> DT?

See my response to your message on patch 1.

> >  +
> >   static struct jz4780_dma_desc *jz4780_dma_desc_alloc(
> >   	struct jz4780_dma_chan *jzchan, unsigned int count,
> >   	enum dma_transaction_type type)
> >  @@ -228,8 +246,15 @@ static void jz4780_dma_desc_free(struct 
> > virt_dma_desc *vdesc)
> >   	kfree(desc);
> >   }
> >
> >  -static uint32_t jz4780_dma_transfer_size(unsigned long val, 
> > uint32_t *shift)
> >  +static const unsigned int jz4780_dma_ord_max[] = {
> >  +	[ID_JZ4770] = 6,
> >  +	[ID_JZ4780] = 7,
> >  +};
>
> So this gives the transfer length supported?

Yes, exactly. The maximum transfer size is (1 << ord).

> --
> ~Vinod