On Thu, Jul 03, 2014 at 07:51:51AM +0300, Peter Ujfalusi wrote: > I have noticed while switching the daVinci audio to dmaengine_pcm that the _3LE > and _3BE support is not working correctly via dmaengine_pcm: > In case of _3LE/_3BE formats the samples are stored in 3 consecutive bytes > without padding it to 4 bytes. This means that the DMA needs to be able to > support 3 bytes word length in order to read/write the samples from memory > correctly. Originally the code treated 24 bits physical length samples as > they were 32 bits which leads to corruption when playing or recording audio. > > To fix the support for 3 bytes physical samples the dma driver also need to have > support for such data arrangement. eDMA does have support for it in HW and the > legacy davinci-pcm platform driver w/o dmaengine was able to support such > formats. > > First step is to add DMA_SLAVE_BUSWIDTH_3_BYTES to dma_slave_buswidth for > engines and users to select 3 bytes as bus width. > > Followed by: > In dmaengine_pcm_set_runtime_hwparams() we should check the slave_caps of the > dma if it supports the give sample physical width of the sample. Based on this > information we initialize the hw.formats: masking out all non supported formats > based on the physical width. > In case the dma driver does not implement the slave_caps the default assumption > is that it supports 1, 2 and 4 bytes widths. Whole series: Acked-by Vinod Koul <vinod.koul@xxxxxxxxx> Yes makes sense to go thru ASoC tree. Mark can you keep this in immutable branch, which I can merge to my tree for any future fixes... -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
