Messages in this thread | | | From | Chunyan Zhang <> | Date | Tue, 4 Dec 2018 11:11:50 +0800 | Subject | Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices |
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Hi Faiz,
On Mon, 3 Dec 2018 at 21:55, Faiz Abbas <faiz_abbas@ti.com> wrote: > > 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.
The check for data is added in sdhci_external_dma_setup() .
> > > > My test with an am335x-evm failed with these patches. Looks like the > > very first SDIO commands failing.
I guess you didn't add 'dmas' in device tree, like patch 3 shows.
> > > > 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: >
Yes, it switched back to ADMA/PIO since sdhci couldn't find 'dmas' property in devicetree.
> [3.111693] Failed to request TX DMA channel.
Ok, I will add a check in sdhci-omap.c before switching to external dma, that should be able to avoid this error logs.
Thanks for the review and test!
Chunyan
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