Created attachment 217869 [details]
Patch for adding DMA support to the uSDHCI of the i.MX6ULL.
I added some workarounds to the sdhci and fsl_sdhci driver so that I can enable DMA support for the i.MX6ULL uSDHCI. NXP did something a bit other then other SDHCI controllers. But as far as I can tell, all patches should work with every normal SDHCI controller too and there shouldn't be a big performance impact.
Note that I use the FreeBSD SDHCI stack via libbsd in RTEMS. So please be aware that this patch isn't tested directly on a FreeBSD kernel but only in a RTEMS application.