The psmouse driver does not create the attributes before userspace is notified of a (all or some?) device's presence. For instance, this causes a udev rule to adjust the speed and sensitivity of a trackpoint not to trigger. Reference: https://github.com/systemd/systemd/commit/f2b8052fb648b788936dd3e85be6a9aca90fbb2f#commitcomment-12251878
We can wish as much as we want for all attributes to be created upfront, but it is not going to happen. Quite often attributes are added to the device by the driver that is bound to it (because without the driver nobody knows how to control hardware behavior). I think the only workable solution is to add an additional uevent (or piggy-back on KOBJ_CHNAGE) that we'd emit once driver is bound to the device, and have udev allow triggering on it.
We have BIND/UNBIND uevents now, for driver-specific attributes userspace should listen to them: commit 1455cf8dbfd06aa7651dcfccbadb7a093944ca65 Author: Dmitry Torokhov <dmitry.torokhov@gmail.com> Date: Wed Jul 19 17:24:30 2017 -0700 driver core: emit uevents when device is bound to a driver There are certain touch controllers that may come up in either normal (application) or boot mode, depending on whether firmware/configuration is corrupted when they are powered on. In boot mode the kernel does not create input device instance (because it does not necessarily know the characteristics of the input device in question). Another number of controllers does not store firmware in a non-volatile memory, and they similarly need to have firmware loaded before input device instance is created. There are also other types of devices with similar behavior. There is a desire to be able to trigger firmware loading via udev, but it has to happen only when driver is bound to a physical device (i2c or spi). These udev actions can not use ADD events, as those happen too early, so we are introducing BIND and UNBIND events that are emitted at the right moment. Also, many drivers create additional driver-specific device attributes when binding to the device, to provide userspace with additional controls. The new events allow userspace to adjust these driver-specific attributes without worrying that they are not there yet. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>