Messages in this thread | | | Subject | Re: [PATCH V3 0/3] Add support for using external dma in SDHCI | From | Faiz Abbas <> | Date | Tue, 4 Dec 2018 16:06:10 +0530 |
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Hi Chunyan,
On 04/12/18 12:54 PM, Chunyan Zhang wrote: > Currently the generic SDHCI code in the Linux kernel supports the SD > standard DMA integrated into the host controller but does not have any > support for external DMA controllers implemented using dmaengine meaning > that custom code is needed for any systems that use a generic DMA > controller with SDHCI which in practice means any SDHCI controller that > doesn't have an integrated DMA controller so we should have this as a > generic feature. > > There are already a number of controller specific drivers that have dmaengine > code, and some could use sdhci.c actually, but needed to implement mmc_ops->request() > in their specific driver for sending command with external dma using dmaengine > framework, with this patchset, them will take advantage of the generic support. > TI's omap controller is the case as an example. > > Any comments are very appreciated. >
Following your comments, I added dmas in dra7.dtsi as shown in the patch below.
https://pastebin.ubuntu.com/p/J4F3xWZv5c/
This time the MMC devices enumerate successfully but I see a bunch of
[ 108.135736] omap-dma-engine 4a056000.dma-controller: t2_desc[10] allocation failed
messages when I try to run a short ltp test.
https://pastebin.ubuntu.com/p/WvRSkxBPpv/
Thanks, Faiz
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