David Gibson wrote: > On Wed, Apr 22, 2009 at 11:41:31PM -0500, Kumar Gala wrote: >> Lets say I had an error driver for our MCM (core to soc coherency >> module). It was getting the base address by using get_immrbase(). >> Today I proposed a proper device node for the MCM block as it doesn't >> exist in .dts today. We add such a node into .dts and I can clean up my >> error driver to use proper device node information. However I've just >> broken any old .dts that didn't have this node. You are saying I need to >> add code into the kernel to create this new node and we have to keep that >> code around for ever in the kernel.. why would I ever bother to actually >> changing anything than. > > Well, again. It's a judgement call, balancing the pain of having to > update the dts files (which depends on how widely deployed the > platform is) versus the pain of having to keep the bacwards > compatibility shim in the kernel.
I agree with this sentiment. I'm only asking for a reasonable attempt at adding backwards compatibility via an isolated code block. Sprinkle in a few comments, and that should be enough. It won't always be possible to add such code, but at the very least, I expect the driver/kernel to clearly indicate what's missing from the device tree. In Kumar's example above, I expect the kernel to say that the MCM node is missing. -- Timur Tabi Linux kernel developer at Freescale _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
