Anton Vorontsov wrote:
On Wed, Oct 22, 2008 at 08:38:03AM -0500, Matt Sealey wrote:
I'm extremely troubled that it is "not used in the code", surely device_type is checked as a legacy for Open Firmware (otherwise a lot of devices may never be detected!),

Checked where?

of_find_device_by_type() goes through it and of_find_compatible_node() - while not directly, checks the type field of the node which is filled in from device_type BEFORE it checks the compatible property.

This isn't specific CHRP/FDT platform code it's in the generic tree scanning functions.

platforms, the CHRP is running real OF, so it is irrelevant if it
checks for device_type = "rtc" or not.)

Except when there is no compatible property because the device is adequately identified by device_type (for instance if you are looking for every serial port on a system, device_type is your only hope without checking for every different KIND of serial port you may ever possibly encounter.. or if you are checking for what kind of console OF attached you to (be it display/keyboard combination or serial or something else).

It's a useful property that should be kept around, you never know when it might be needed :D but of course since it's not in ePAPR, no point in shoving it in when "compatible" describes your board very very accurately anyway (except when you have no need to be very very accurate and are just looking for serial ports... :)

--
Matt Sealey <[EMAIL PROTECTED]>
Genesi, Manager, Developer Relations
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev

Reply via email to