On 11/14/2016 12:53 PM, Russell King - ARM Linux wrote:
> On Tue, Oct 25, 2016 at 01:50:19PM +0300, Peter Ujfalusi wrote:
>> Based on the src/dst_port_window_size - if it is set - configure the DMA
>> channel to use double indexing in order to be able to loop within the
>> address window.
>>
>> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
>> ---
>> drivers/dma/omap-dma.c | 45 +++++++++++++++++++++++++++++++++++++++++++--
>> 1 file changed, 43 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
>> index 025f499cb20d..29350f936154 100644
>> --- a/drivers/dma/omap-dma.c
>> +++ b/drivers/dma/omap-dma.c
>> @@ -166,6 +166,9 @@ enum {
>> CSDP_DST_BURST_16 = 1 << 14,
>> CSDP_DST_BURST_32 = 2 << 14,
>> CSDP_DST_BURST_64 = 3 << 14,
>> + CSDP_WRITE_NON_POSTED = (0 << 16),
>> + CSDP_WRITE_POSTED = (1 << 16),
>> + CSDP_WRITE_LAST_NON_POSTED = (2 << 16),
>
> Why the useless parens?
I will get rid of them.
>
>> + if (port_window) {
>> + d->ccr |= CCR_SRC_AMODE_DBLIDX;
>> + d->ei = 1;
>> + d->fi = (-1) * (port_window - 1);
>
> You know that's 1 - port_window, or -(port_window - 1).
Yes, I know. "-(port_window - 1)" might be a bit better.
>
>> +
>> + 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;
>
> Why these divisions? Wouldn't >= be more suitable here? Do they even
> make sense here?
I'll revisit these.
>
>> + } else {
>> + d->ccr |= CCR_SRC_AMODE_CONSTANT;
>> + }
>> } else {
>> - d->ccr |= CCR_DST_AMODE_CONSTANT | CCR_SRC_AMODE_POSTINC;
>> d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
>> +
>> + d->ccr |= CCR_SRC_AMODE_POSTINC;
>> + if (port_window) {
>> + d->ccr |= CCR_DST_AMODE_DBLIDX;
>> +
>> + if (port_window / 64)
>> + d->csdp = CSDP_DST_BURST_64 | CSDP_DST_PACKED;
>> + else if (port_window / 32)
>> + d->csdp = CSDP_DST_BURST_32 | CSDP_DST_PACKED;
>> + else if (port_window / 16)
>> + d->csdp = CSDP_DST_BURST_16 | CSDP_DST_PACKED;
>
> Ditto.
>
>> + } else {
>> + d->ccr |= CCR_DST_AMODE_CONSTANT;
>> + }
>> }
>>
>> d->cicr = CICR_DROP_IE | CICR_BLOCK_IE;
>> @@ -945,6 +979,9 @@ static struct dma_async_tx_descriptor
*omap_dma_prep_slave_sg(
>> d->ccr |= CCR_TRIGGER_SRC;
>>
>> d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE;
>> +
>> + if (port_window)
>> + d->csdp |= CSDP_WRITE_LAST_NON_POSTED;
>> }
>> if (od->plat->errata & DMA_ERRATA_PARALLEL_CHANNELS)
>> d->clnk_ctrl = c->dma_ch;
>> @@ -970,6 +1007,10 @@ static struct dma_async_tx_descriptor
*omap_dma_prep_slave_sg(
>> osg->addr = sg_dma_address(sgent);
>> osg->en = en;
>> osg->fn = sg_dma_len(sgent) / frame_bytes;
>> + if (port_window && dir == DMA_MEM_TO_DEV) {
>> + osg->ei = 1;
>> + osg->fi = (-1) * (port_window - 1);
>
> Same as above.
>
--
Péter
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