Messages in this thread | | | Date | Wed, 1 Oct 2014 10:27:05 +0200 | From | Maxime Ripard <> | Subject | Re: [PATCH 7/9] dmaengine: Move slave caps to dma_device |
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On Sat, Sep 27, 2014 at 10:28:47AM +0100, Russell King - ARM Linux wrote: > On Sat, Sep 27, 2014 at 10:54:43AM +0200, Maxime Ripard wrote: > > The previous code was relying on the fact that the slave_caps were to be > > defined on a per channel basis. > > > > However, this proved to be a bit overkill, since every driver filling these so > > far were hardcoding it, disregarding which channel was actually given. > > > > Add these capabilities to the dma_device structure, so that drivers can just > > provide them at probe time, and be done with it. > > This is also buggy for the same reason as patch 6.
Indeed
> The only way to do this is to either have a flag day, fixing all drivers > at once (which isn't going to happen) or leave the caps code as-is, and > provide a library function which drivers can hook into the caps callback > which retrieves the information from dma_device. > > That way, DMA engine drivers which are using the new method can just > install the new function, and those which haven't been updated with > capabilities can carry on as they are, and are detectable to drivers.
Which is pretty much the current behaviour, isn't it?
> What would be acceptable is to have the DMA engine registration function > spot the lack of DMA caps function and print a warning at boot to > encourage people to add it.
That would be an option too.
Maxime
-- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com [unhandled content-type:application/pgp-signature] | |