Hi Vinod,
On 11 April 2018 at 17:40, Vinod Koul <vinod.k...@intel.com> wrote:
> On Tue, Apr 10, 2018 at 03:46:07PM +0800, Baolin Wang wrote:
>> This patch adds the 'device_config' and 'device_prep_slave_sg' interfaces
>> for users to configure DMA.
>>
>> Signed-off-by: Baolin Wang <baolin.w...@linaro.org>
>> ---
>> drivers/dma/sprd-dma.c | 48
>> ++++++++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 48 insertions(+)
>>
>> diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
>> index f8038de..c923fb0 100644
>> --- a/drivers/dma/sprd-dma.c
>> +++ b/drivers/dma/sprd-dma.c
>> @@ -869,6 +869,52 @@ static int sprd_dma_config(struct dma_chan *chan,
>> struct sprd_dma_desc *sdesc,
>> return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);
>> }
>>
>> +static struct dma_async_tx_descriptor *
>> +sprd_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
>> + unsigned int sglen, enum dma_transfer_direction dir,
>> + unsigned long flags, void *context)
>> +{
>> + struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
>> + struct sprd_dma_config *slave_cfg = &schan->slave_cfg;
>> + struct sprd_dma_desc *sdesc;
>> + struct scatterlist *sg;
>> + int ret, i;
>> +
>> + /* TODO: now we only support one sg for each DMA configuration. */
>> + if (!is_slave_direction(slave_cfg->config.direction) || sglen > 1)
>
> the slave direction check seems wrong to me. .device_config shall give you
> dma_slave_config. You should check here if dir passed is slave or not. If
> you want to check parameters in slave_config then please use .device_config
Correct. Sorry I missed this and I will fix it in next version.
>
>> + return NULL;
>> +
>> + sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
>> + if (!sdesc)
>> + return NULL;
>> +
>> + for_each_sg(sgl, sg, sglen, i) {
>> + if (slave_cfg->config.direction == DMA_MEM_TO_DEV)
>> + slave_cfg->config.src_addr = sg_dma_address(sg);
>
> Nope slave_config specifies peripheral address and not memory one passed here
OK. Thanks for your comments.
--
Baolin.wang
Best Regards
