On 05/24/2013 07:54 AM, Vinod Koul wrote:
On Fri, May 24, 2013 at 07:58:04AM +0200, Lars-Peter Clausen wrote:
This one needs both.
- jzcfg.mode = JZ4740_DMA_MODE_SINGLE;
- jzcfg.request_type = config->slave_id;
- chan->config = *config;
- jz4740_dma_configure(chan->jz_chan, &jzcfg);
- return 0;
You are NOT use src_addr/dstn_addr? How else are you passing the periphral address?
I'm saving the whole config, which will later be used to retrieve the source or dest address.
well I missed that and it is a bad idea. You dont know when client has freed/thrown the pointer so copy this instead..
I do copy the full config, not just the pointer to the config. Although src_addr and dest_addr are the only two fields which are used later on at this point. So I could change it to just copy src_addr and dest_addr, or well just one of them depending on the direction.
+}
[...]
+static int jz4740_dma_alloc_chan_resources(struct dma_chan *c) +{
- struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
- chan->jz_chan = jz4740_dma_request(chan, NULL);
- if (!chan->jz_chan)
return -EBUSY;- jz4740_dma_set_complete_cb(chan->jz_chan, jz4740_dma_complete_cb);
- return 0;
Zero is not expected value, you need to return the descriptors allocated sucessfully.
Well, zero descriptors have been allocated. As far as I can see only a negative return value is treated as an error. Also the core doesn't seem to use the return value for anything else but checking if it is an error.
This is the API defination
- @device_alloc_chan_resources: allocate resources and return the
number of allocated descriptors
But 0 is still the number of descriptors that have been pre-allocated.
- Lars