On 08/21/16 18:40, Ran Shalit wrote: > On Mon, Aug 1, 2016 at 9:25 AM, Peter Ujfalusi <peter.ujfalusi@xxxxxx> wrote: >> On 07/30/16 17:07, Ran Shalit wrote: >>> >>> בתאריך 25 ביול 2016 09:49, "Peter Ujfalusi" <peter.ujfalusi@xxxxxx >>> <mailto:peter.ujfalusi@xxxxxx>> כתב: >>>> >>>> On 07/23/16 17:39, Ran Shalit wrote: >>>>> Hello, >>>>> >>>>> I try to use DMA in a ethernet driver I am writing (for OMAP4460). >>>>> I know there is the edma API which can be used with OMAP: >>>>> http://processors.wiki.ti.com/index.php/EDMA_sample_test_application >>>> >>>> eDMA is not available on OMAPs. We have sDMA (system DMA, or DMA4). >>>> >>>>> But on viewing the ethernet driver in the kernel tree, I can't find >>>>> anywhere using these APIs. >>>>> I assume there is some framework in between which is used instead (and >>>>> probably calls the edma APIs directly). >>>>> >>>>> 1. Do you think for simplicity I can use the edma APIs directly ? >>>> >>>> You should not use direct API. eDMA does not have it anymore and while sDMA >>>> still have legacy API, we are working on to remove it. >>> >>> Just for understanding, >>> What is these sDMA API? >>> I could not find these APIs. >> >> Please use dmaengine only. Avoid using the sDMA legacy API >> (include/linux/omap-dma.h) it is going to be removed hopefully sooner than later. >> >>>> Please use the dmaengine API to configure the DMA. This way your driver will >>>> be portable also. > > Hi, > > I try to use dmaengine (using dart board), with dmatest.ko, With dmatest you can only test MEM_TO_MEM type of transfers, like memcpy, XOR, etc. > but seems that nothing happens because /sys/class/dma is empty. How can your board even boot up w/o dma? > Is there a way to register the dma channels (using dart board file > probably) so that they appear ? OMAP4 _needs_ dmaengine to be available in order to boot, do you have DMA_OMAP enabled in your kernel? What is the kernel versiuon you are using? > > > Regards, > Ran > > >>> >>>> >>>>> 2.Is there any example which shows how to use DMA (which shall call >>>>> the edma, and shall result in triggering a dma trsnaction in OMAP) ? >>>> >>>> git grep dmaengine_prep_dma_sg >>>> or >>>> git grep dmaengine_terminate_all >>>> >>>> will show you the drivers using dmaengine. >>>> >>>> -- >>>> Péter >>> >> >> >> -- >> Péter -- Péter -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
