Hi Marcel,

quoted

the commit message is misleading me. If I build something with ACPI or DT support, then modinfo will show all modalias information for ACPI and DT compatible strings. What else does udev/modprobe actually need? Is something broken with the modalias export?

The main purpose is to autoload drivers for devices that have been
created via sysfs or another module.

Eg1: We have a serial port on a standard computer that has connected a
GPS module. Since it is something that is not in the ACPI nor the DT
table the user will run

echo serdev_gps > /sys/bus/serial/devices/serial0/new_device

Eg2 module: https://github.com/ribalda/linux/blob/415bb3f0076c2b846ebe5409589b8e1e3004f55a/drivers/tty/serdev/test_platform.c

Modprobe does not know what module to load for that device unless
there is a matching MODULE_DEVICE_TABLE
Today, we have the same functionality for i2c devices
https://www.kernel.org/doc/Documentation/i2c/instantiating-devices

but why does this have to be the driver name? I would rather say, create a generic string that describes the hardware and then use that. I think you also want the special handling, as from USB for example, that lets you reference an existing .compatible or ACPI ID as reference so that the driver_data is copied.

Regards

Marcel