Messages in this thread |  | | Subject | Re: [PATCH v7 05/11] dmaengine: Introduce DMA-device device_caps callback | From | Dave Jiang <> | Date | Tue, 14 Jul 2020 09:18:16 -0700 |
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On 7/14/2020 9:08 AM, Vinod Koul wrote: > On 13-07-20, 13:55, Dave Jiang wrote: >> >> >> On 7/10/2020 2:38 AM, Serge Semin wrote: >>> On Fri, Jul 10, 2020 at 11:45:03AM +0300, Andy Shevchenko wrote: >>>> On Fri, Jul 10, 2020 at 01:45:44AM +0300, Serge Semin wrote: >>>>> There are DMA devices (like ours version of Synopsys DW DMAC) which have >>>>> DMA capabilities non-uniformly redistributed between the device channels. >>>>> In order to provide a way of exposing the channel-specific parameters to >>>>> the DMA engine consumers, we introduce a new DMA-device callback. In case >>>>> if provided it gets called from the dma_get_slave_caps() method and is >>>>> able to override the generic DMA-device capabilities. >>>> >>> >>>> In light of recent developments consider not to add 'slave' and a such words to the kernel. >>> >>> As long as the 'slave' word is used in the name of the dma_slave_caps >>> structure and in the rest of the DMA-engine subsystem, it will be ambiguous >>> to use some else terminology. If renaming needs to be done, then it should be >>> done synchronously for the whole subsystem. >> >> What about just calling it dma_device_caps? Consider this is a useful >> function not only slave DMA will utilize this. I can see this being useful >> for some of my future code with idxd driver. > > Some of the caps may make sense to generic dmaengine but few of them do > not :) While at it, am planning to make it dmaengine_periph_caps to > denote that these are dmaengine peripheral capabilities. >
If the function only passes in periph_caps, how do we allow the non periph DMA utilize this function?
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