On Thu, Sep 27, 2018 at 5:25 PM Li Yang <leoyang.li@xxxxxxx> wrote: > > Hi Rob and Grant, > > Various device tree specs are recommending to include all the > potential compatible strings in the device node, with the order from > most specific to most general. But it looks like Linux kernel doesn't > provide a way to bind the device to the most specific driver, however, > the first registered compatible driver will be bound. > > As more and more generic drivers are added to the Linux kernel, they > are competing with the more specific vendor drivers and causes problem > when both are built into the kernel. I'm wondering if there is a > generic solution (or in plan) to make the most specific driver bound > to the device. Or we have to disable the more general driver or > remove the more general compatible string from the device tree? It's been a known limitation for a long time. However, in practice it doesn't seem to be a common problem. Perhaps folks just remove the less specific compatible from their DT (though that's not ideal). For most modern bindings, there's so many other resources beyond compatible (clocks, resets, pinctrl, etc.) that there are few generic drivers that can work. I guess if we want to fix this, we'd need to have weighted matching in the driver core and unbind drivers when we get a better match. Though it could get messy if the better driver probe fails. Then we've got to rebind to the original driver. Do you have a specific case where you hit this? Rob
