Subject: Re: [PATCH 6/7] tty/powerpc: introduce the ePAPR embedded hypervisor byte channel driver

From: Timur Tabi <[email-masked]>
Date: Thu, 19 May 2011 09:27:52 -0500

Greg KH wrote:
> Why do this conversion in the driver?  Shouldn't that be something that
> userspace worries about?

The udbg interface is a very early kernel printk interface.  I don't know what
the "u" stands for, but "dbg" is for "debug".  The udbg interface is removed
once a normal console driver kicks in.

This is why I need to specify the byte channel handle via Kconfig.  This code is
used so early that not even the device tree is available.

All of the udbg_putc functions do this.

-- 
Timur Tabi
Linux kernel developer at Freescale