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

Timur Tabi <[email protected]> Thu, 19 May 2011 09:27:52 -0500
Newsgroups org.kernel.vger.linux-console,org.kernel.vger.linux-kernel,org.ozlabs.lists.linuxppc-dev
Message-ID <[email protected]>
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