Messages in this thread | | | Subject | Re: [PATCH] [RFC] dmaengine: add fifo_size member | From | Jon Hunter <> | Date | Thu, 6 Jun 2019 15:36:03 +0100 |
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On 06/06/2019 15:26, Jon Hunter wrote:
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>>> If I understood everything correctly, the FIFO buffer is shared among >>> all of the ADMA clients and hence it should be up to the ADMA driver to >>> manage the quotas of the clients. So if there is only one client that >>> uses ADMA at a time, then this client will get a whole FIFO buffer, but >>> once another client starts to use ADMA, then the ADMA driver will have >>> to reconfigure hardware to split the quotas. >>> >> >> You could also simply hardcode the quotas per client in the ADMA driver >> if the quotas are going to be static anyway. > > Essentially this is what we have done so far, but Sameer is looking for > a way to make this more programmable/flexible. We can always do that if > there is no other option indeed. However, seems like a good time to see > if there is a better way.
My thoughts on resolving this, in order of preference, would be ...
1. Add a new 'fifo_size' variable as Sameer is proposing. 2. Update the ADMA driver to use src/dst_maxburst as the fifo size and then have the ADMA driver set a suitable burst size for its burst size. 3. Resort to a static configuration.
I can see that #1 only makes sense if others would find it useful, otherwise #2, may give us enough flexibility for now.
Cheers Jon
-- nvpublic
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