Hi, On 03/12/18 5:45 PM, Faiz Abbas wrote: > Hi, > >> +static void sdhci_external_dma_prepare_data(struct sdhci_host *host, >> + struct mmc_command *cmd) >> +{ > > Please add a condition for data == NULL here. This was already pointed > out by Adrian in v2. > > My test with an am335x-evm failed with these patches. Looks like the > very first SDIO commands failing. > > https://pastebin.ubuntu.com/p/Y2RDjSKpgd/ > > Currently am335x-evm is using omap_hsmmc driver. I added the following > patch to make it work with sdhci_omap. > > https://pastebin.ubuntu.com/p/VTGrCbJxY3/ > > Will look deeper into this. Please ping if you need any more information. > So I disabled DMA in the driver altogether and still got the same messages on am335x-evm in PIO mode. Looks like something more is required for it to be supported. I instead shifted to a dra71-evm which supports both ADMA and external DMA. Here is the log: https://pastebin.ubuntu.com/p/mcJmgcjQsp/ The interface fundamentally works but it complains with the following error: [3.111693] Failed to request TX DMA channel. Thanks, Faiz