Re: [PATCHv3 08/16] staging: vme_user: provide DMA functionality

[Dmitry Kalinkin]

> On 08 Jul 2015, at 16:57, Martyn Welch <martyn.welch@xxxxxx> wrote:
> 
> 
> 
> On 07/07/15 11:52, Dmitry Kalinkin wrote:
>> The API I had in mind would have only vme_master_read and
>> vme_master_write that would take absolute addresses (not relative to
>> any window). These variants of access functions would then try to
>> reuse any window that is already able to serve the request or wait
>> for a free window and reconfigure it for the need of the request.
> 
> I'm a little concerned by the latency this might cause, especially if there is one device which is negatively affected by latency. Handling RORA interrupts would be "interesting" if all the windows were dynamically allocated at the time at which an interrupt came in.
Latency-critical windows can be statically allocated using current resource based API.--
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