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Does the Linux-3.10.x distro support imx-sdma memory to memory transfer using the dmaengine interface?

Question asked by K Maier on Jan 29, 2014
Latest reply on Jan 30, 2014 by K Maier

The Linux-3.0.35 distributrion supported sdma mem to mem transfers using the dmaengine api.  The imx-sdma driver supported this using two scater gather lists.  The imx-sdma would use the ap_2_ap script.  This support is no longer in the Linux-3.10.9 distribution.


1. Is this supported in the Linux-3.10.9 or latter distributions?

2. If yes, how has the interface changed from Linux-3.0.35?

3. If no, was there a reason for this feature removal?


Here is a quote from the 3.0.35 imx-sdma driver.


     * For SDMA M2M use, we need 2 scatterlists, the src addresses are

     * stored in the first sg, and the dst addresses are stored in the

     * second sg. In the former code, when the first sg entered 'sdma_

     * prep_slave_sg', 'sdmac->status' would be set to 'DMA_IN_PROGRESS',

     * and the second sg would return 'NULL' when entered 'sdma_prep_slave

     * _sg'. To avoid this error, in the code, we check if for M2M use,

     * the second sg will not return 'NULL' when enters 'sdma_prep_slave

     * _sg'.



Thanks to anyone for input on this issue!!