Am Freitag, den 13.10.2017, 12:25 +0100 schrieb Mark Brown:
On Fri, Oct 13, 2017 at 12:43:46PM +0200, Lucas Stach wrote:
The commit [1] which changed imx-pcm-dma to derive the pcm_config from the attached dmaengine introduced a regression on the supported sample formats, as imx-sdma doesn't properly advertise all the supported slave bus widths.
How did this work previously - shouldn't we have failed to use the unadvertised bus widths? I'd expect the framework to be providing error checking for the clients here.
No, if the sound PCM implementation explicitly provides a pcm_config with the hw.formats set to 0, the core only looks at the DAI supported formats. Now that we derive the pcm_config from the dmaengine hw.formats gets filled with formats supported by the dmaengine, which is then used as an additional constraint by the core.
Regards, Lucas