Messages in this thread | | | Date | Fri, 17 Oct 2014 13:23:56 +0200 | From | Maxime Ripard <> | Subject | Re: [PATCH v2 2/2] Documentation: dmaengine: Add a documentation for the dma controller API |
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Hi Laurent,
Just getting back on something...
On Mon, Oct 06, 2014 at 03:09:48PM +0300, Laurent Pinchart wrote: > > + * device_prep_dma_* > > + - These functions are matching the capabilities you registered > > + previously. > > + - These functions all take the buffer or the scatterlist relevant > > + for the transfer being prepared, and should create a hardware > > + descriptor or a list of descriptors from it > > + - These functions can be called from an interrupt context > > + - Any allocation you might do should be using the GFP_NOWAIT > > + flag, in order not to potentially sleep, but without depleting > > + the emergency pool either. > > You could add "Drivers should try to preallocate the data structures they > require to prepare a transfer."
Isn't that obvious?
I mean, if we're in this function, we're already preparing a transfer... And I would expect any programmer that followed CS101 to be able to allocate the memory it needs :)
The rest of the issues have been fixed, thanks! Maxime
-- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com [unhandled content-type:application/pgp-signature] | |