Messages in this thread | | | From | Kay Sievers <> | Date | Thu, 22 Nov 2012 20:17:32 +0100 | Subject | Re: [RFC] driver-core: Remove dummy 'platform_bus' |
| |
On Wed, Nov 21, 2012 at 3:52 PM, Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote: > On Wed, Nov 21, 2012 at 02:44:31PM +0000, Grant Likely wrote: >> The "platform_bus" (note: not platform_bus_type) only exists as an empty >> directory to put platform devices into. However, it really doesn't make >> sense to segregate all the platform devices into a sub directory when >> typically they are memory mapped devices that doen't go through any >> particular bus. Particularly on embedded type platforms the platform_bus >> directory doesn't add anything. >> >> However, this will probably just end up breaking some userspace that >> depends on the /sys/devices/platform/ path to be present (no matter how >> much we protest that userspace must not depend on paths in sysfs). So >> while I'm seriously proposing this change, it may just be unacceptable >> ABI breakage > > If the devices don't show up under platform/ where are they going to be > at now, virtual/ ? That doesn't sound like a good plan, they should be > somewhere "useful".
Just a note to keep in mind: We usually need and want devices to have a bus or class. Devices without a "subsystem" are invisible to udev, and do not get proper coldplug support at bootup.
Kay
| |