Messages in this thread |  | | Subject | Re: [PATCH 0/3] dmaengine: Stear users towards dma_request_slave_chan() | From | Peter Ujfalusi <> | Date | Mon, 3 Feb 2020 12:59:13 +0200 |
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Hi Andy,
On 03/02/2020 12.37, Andy Shevchenko wrote: > On Mon, Feb 3, 2020 at 12:32 PM Peter Ujfalusi <peter.ujfalusi@ti.com> wrote: > >> dma_request_slave_channel_reason() no longer have user in mainline, it >> can be removed. >> >> Advise users of dma_request_slave_channel() and >> dma_request_slave_channel_compat() to move to dma_request_slave_chan() > > How? There are legacy ARM boards you have to care / remove before. > DMAengine subsystem makes a p*s off decisions
The dma_slave_map support is added few years back for the legacy ARM boards, because we do care. daVinci, OMAP1, pxa, s3cx4xx and even m68k/coldfire moved over.
Imho it is confusing to have 4+ APIs to do the same thing, but in a slightly different way.
> without taking care of > (I'm talking now about dma release callback, for example) end users.
I have been converting users in the background, but the _compat() is a bit more problematic as I need to maintainers of those legacy platforms to craft the map. If they care.
Obviously the APIs are not going to be removed if we have a single user and if there is clearly a need for something the _compat() was doing and it can not be done via the dma_slave_map, then rest assured there will be a clean API to achieve just that.
> They will be scary for no reason.
There is a reason: to clean up the API to make it non confusing for the users. New drivers should not use the old API i new code and developers tend to pick the API they use after a quick 'git grep dma_request_' and see what the majority is using.
- Péter
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
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