2016-11-25 06:03:00

by Vinod Koul

Subject: Re: [PATCH v2 2/2] dmaengine: omap-dma: Support for slave devices with data port window

On Thu, Nov 17, 2016 at 02:50:17PM +0200, Peter Ujfalusi wrote:
> @@ -921,11 +931,45 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
>
> d->ccr = c->ccr | CCR_SYNC_FRAME;
> if (dir == DMA_DEV_TO_MEM) {
> - d->ccr |= CCR_DST_AMODE_POSTINC | CCR_SRC_AMODE_CONSTANT;
> d->csdp = CSDP_DST_BURST_64 | CSDP_DST_PACKED;
> +
> + d->ccr |= CCR_DST_AMODE_POSTINC;
> + if (port_window) {
> + d->ccr |= CCR_SRC_AMODE_DBLIDX;
> + d->ei = 1;
> + /*
> + * One frame covers the port_window and by configure
> + * the source frame index to be -1 * (port_window - 1)
> + * we instruct the sDMA that after a frame is processed
> + * it should move back to the start of the window.
> + */
> + d->fi = -(port_window - 1);
> +
> + if (port_window >= 64)
> + d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
> + else if (port_window >= 32)
> + d->csdp = CSDP_SRC_BURST_32 | CSDP_SRC_PACKED;
> + else if (port_window >= 16)
> + d->csdp = CSDP_SRC_BURST_16 | CSDP_SRC_PACKED;

this and other would look better with a switch..

--
~Vinod

2016-11-25 09:38:58

by Peter Ujfalusi

Subject: Re: [PATCH v2 2/2] dmaengine: omap-dma: Support for slave devices with data port window

On 11/25/2016 08:12 AM, Vinod Koul wrote:
> On Thu, Nov 17, 2016 at 02:50:17PM +0200, Peter Ujfalusi wrote:
>> @@ -921,11 +931,45 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
>>
>> d->ccr = c->ccr | CCR_SYNC_FRAME;
>> if (dir == DMA_DEV_TO_MEM) {
>> - d->ccr |= CCR_DST_AMODE_POSTINC | CCR_SRC_AMODE_CONSTANT;
>> d->csdp = CSDP_DST_BURST_64 | CSDP_DST_PACKED;
>> +
>> + d->ccr |= CCR_DST_AMODE_POSTINC;
>> + if (port_window) {
>> + d->ccr |= CCR_SRC_AMODE_DBLIDX;
>> + d->ei = 1;
>> + /*
>> + * One frame covers the port_window and by configure
>> + * the source frame index to be -1 * (port_window - 1)
>> + * we instruct the sDMA that after a frame is processed
>> + * it should move back to the start of the window.
>> + */
>> + d->fi = -(port_window - 1);
>> +
>> + if (port_window >= 64)
>> + d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
>> + else if (port_window >= 32)
>> + d->csdp = CSDP_SRC_BURST_32 | CSDP_SRC_PACKED;
>> + else if (port_window >= 16)
>> + d->csdp = CSDP_SRC_BURST_16 | CSDP_SRC_PACKED;
>
> this and other would look better with a switch..

I'm not sure if it will be any better:

switch (port_window) {
case 0 ... 15:
break;
case 16 ... 31:
d->csdp = CSDP_SRC_BURST_16 | CSDP_SRC_PACKED;
break;
case 32 ... 63:
d->csdp = CSDP_SRC_BURST_32 | CSDP_SRC_PACKED;
break;
default:
d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
break;
}


--
P?ter

2016-11-29 03:07:47

by Vinod Koul

Subject: Re: [PATCH v2 2/2] dmaengine: omap-dma: Support for slave devices with data port window

On Fri, Nov 25, 2016 at 11:38:51AM +0200, Peter Ujfalusi wrote:
>
>
> On 11/25/2016 08:12 AM, Vinod Koul wrote:
> > On Thu, Nov 17, 2016 at 02:50:17PM +0200, Peter Ujfalusi wrote:
> >> @@ -921,11 +931,45 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
> >>
> >> d->ccr = c->ccr | CCR_SYNC_FRAME;
> >> if (dir == DMA_DEV_TO_MEM) {
> >> - d->ccr |= CCR_DST_AMODE_POSTINC | CCR_SRC_AMODE_CONSTANT;
> >> d->csdp = CSDP_DST_BURST_64 | CSDP_DST_PACKED;
> >> +
> >> + d->ccr |= CCR_DST_AMODE_POSTINC;
> >> + if (port_window) {
> >> + d->ccr |= CCR_SRC_AMODE_DBLIDX;
> >> + d->ei = 1;
> >> + /*
> >> + * One frame covers the port_window and by configure
> >> + * the source frame index to be -1 * (port_window - 1)
> >> + * we instruct the sDMA that after a frame is processed
> >> + * it should move back to the start of the window.
> >> + */
> >> + d->fi = -(port_window - 1);
> >> +
> >> + if (port_window >= 64)
> >> + d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
> >> + else if (port_window >= 32)
> >> + d->csdp = CSDP_SRC_BURST_32 | CSDP_SRC_PACKED;
> >> + else if (port_window >= 16)
> >> + d->csdp = CSDP_SRC_BURST_16 | CSDP_SRC_PACKED;
> >
> > this and other would look better with a switch..
>
> I'm not sure if it will be any better:
>
> switch (port_window) {
> case 0 ... 15:
> break;
> case 16 ... 31:
> d->csdp = CSDP_SRC_BURST_16 | CSDP_SRC_PACKED;
> break;
> case 32 ... 63:
> d->csdp = CSDP_SRC_BURST_32 | CSDP_SRC_PACKED;
> break;
> default:
> d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
> break;
> }

Yeah agree with you on this..

--
~Vinod