[Sound-open-firmware] [RFC PATCH 3/6] dma: introduce new API for requesting DMAC

[Jie, Yang]

>-----Original Message-----
>From: sound-open-firmware-bounces at alsa-project.org [mailto:sound-open-
>firmware-bounces at alsa-project.org] On Behalf Of Ranjani Sridharan
>Sent: Friday, June 8, 2018 8:25 AM
>To: Liam Girdwood <liam.r.girdwood at linux.intel.com>; Keyon Jie
><yang.jie at linux.intel.com>; sound-open-firmware at alsa-project.org
>Cc: rander.wang <rander.wang at linux.intel.com>
>Subject: Re: [Sound-open-firmware] [RFC PATCH 3/6] dma: introduce new API for
>requesting DMAC
>
>On Thu, 2018-06-07 at 20:45 +0100, Liam Girdwood wrote:
>> On Thu, 2018-06-07 at 10:26 -0700, Ranjani Sridharan wrote:
>> > I did some experiments with the new API suggested and ran into
>> > issues with the APL platform. And the problem was with the ipc DMAC.
>> > What type would I use for ipc? We've been using the GP LP DMA for
>> > ipc but with this API, there's no way for me to request a GPLP DMA
>> > and requesting a capability of mem_to_mem or mem_dev/dev_to_mem,
>> > just to get a GP_LP DMA , would be misleading. So I think I am
>> > leaning back to the original solution proposed by Liam.
>> >
>> > We will have to qualify DMAC with a type and copy cap like like
>> > these:
>> >
>> > DMAC_TYPE would be one of: GP_LP_DMA, GP_HP_DMA, Host_DMA or Link
>> > DMA
>> >
>> > DMAC_COPY_CAP would be one of: REDA, WRITE or DUPLEX
>> >
>> > With this it is easy for me to choose the dma like this:
>> >
>> > host: dma_get(Host_DMA, READ/WRITE, FLAGS)
>> > dai: dma_get(GP_LP_DMA, READ/WRITE, FLAGS) page table:
>> > dma_get(HOST_DMA, READ, FLAGS)
>> > ipc: dma_get(GP_LP_DMA, DUPLEX)
>>
>> ipc is host DMA.
>
>This is what is breaking for me atm on APL. In the current implementation, we are
>using  GP_LP_DMA for ipc.

Are you meaning DMA trace with "ipc"? if so, you should use host input DMA.

Thanks,
~Keyon

>
>>
>> Before doing v3, maybe best to reply with proposed flags and types ?
>>
>> Thanks
>>
>> Liam
>>
>> >
>> > Let me know your thoughts.
>>
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