Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev | Date | Fri, 02 Sep 2016 15:10:34 +0200 |
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On Friday, September 2, 2016 12:55:33 PM CEST Robin Murphy wrote: > > Huh? There's only no DMA description in DT if the device can be assumed > to be happy with the defaults. Anything else should be using > "dma-ranges", "dma-coherent", etc. to describe non-default integration > aspects. For devices with an inherent fixed addressing capability !=32 > bits, then it's down to the driver to call dma_set_mask() appropriately > to override the default 32-bit mask (which is not unique to OF-probed > devices either).
The iommu configuration would be the main other one worth mentioning.
Note that there is a known bug with dma_set_mask(), which always succeeds at the moment, even if the dma-ranges limit the possible addresses in a way that should fail.
Arnd
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