[PATCHv4 3/6] dmaengine: mv_xor: remove support for dmacap,* DT properties
Vinod Koul
vinod.koul at intel.com
Wed Aug 19 10:00:45 PDT 2015
On Mon, Jul 27, 2015 at 12:44:05PM +0200, Thomas Petazzoni wrote:
> Vinod,
>
> On Wed, 22 Jul 2015 10:46:53 +0530, Vinod Koul wrote:
>
> > > xor01 {
> > > interrupts = <52>;
> > > - dmacap,memcpy;
> > > - dmacap,xor;
> > > - dmacap,memset;
> > I maybe wrong but there was an assumption that DT properties, even if bad
> > are always there as they need to be treated as kernel ABI.
> >
> > How will it work if someone has older DT implementation or older driver?
>
> Supporting a new DT with an old kernel has never been part of the
> requirements of the DT ABI stability.
>
> Supporting an old DT with a new kernel is the actual requirement. And
> the patch I'm proposing does not break this at all: a new kernel will
> simply ignore those dmacap,* properties from an old DT, and the driver
> automatically knows by itself what are the capabilities of the
> different XOR engines.
>
> Therefore, there is no backward compatibility issue introduced by this
> patch.
Yes tht is correct
--
~Vinod
More information about the linux-arm-kernel
mailing list