On Sat, Aug 15, 2015 at 01:49:42PM +0000, Lin, Mengdong wrote:
Is there some topic branch which can accept topology patches for next kernel release? Can we change topology ABI in v4.3?
You're not quite getting the issue here - the problem is that once we have released the ABI we need to keep supporting applications using it so we can't just change the ABI, we also need to keep compatibility code for the original ABI. This makes it a lot more effort to change things.
Now only Intel SKL driver is using topology code, so the affect should be limited. And I feel using bitwise flag is simpler in both user space and in kernel coding. We can increase the topology ABI number when there is ABI change, and the topology driver always checks this version.
Someone else may take this kernel and use it in their product, or some distro may decide to ship v4.2 as their kernel. Once it's in a release we have to assume someone is going to start relying on the ABI.