From mboxrd@z Thu Jan 1 00:00:00 1970 From: Timur Tabi Subject: Re: [PATCH 6/7] tty/powerpc: introduce the ePAPR embedded hypervisor byte channel driver Date: Thu, 19 May 2011 09:27:52 -0500 Message-ID: <4DD528E8.20203@freescale.com> References: <1305813272-31826-1-git-send-email-timur@freescale.com> <1305813272-31826-7-git-send-email-timur@freescale.com> <20110519142225.GC21441@kroah.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110519142225.GC21441@kroah.com> Sender: linux-console-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Greg KH Cc: kumar.gala@freescale.com, benh@kernel.crashing.org, akpm@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-console@vger.kernel.org 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