From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from VA3EHSOBE009.bigfish.com (va3ehsobe006.messaging.microsoft.com [216.32.180.16]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (Client CN "mail.global.frontbridge.com", Issuer "Cybertrust SureServer Standard Validation CA" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id B612DB6F8A for ; Fri, 20 May 2011 00:28:19 +1000 (EST) Message-ID: <4DD528E8.20203@freescale.com> Date: Thu, 19 May 2011 09:27:52 -0500 From: Timur Tabi MIME-Version: 1.0 To: Greg KH Subject: Re: [PATCH 6/7] tty/powerpc: introduce the ePAPR embedded hypervisor byte channel driver References: <1305813272-31826-1-git-send-email-timur@freescale.com> <1305813272-31826-7-git-send-email-timur@freescale.com> <20110519142225.GC21441@kroah.com> In-Reply-To: <20110519142225.GC21441@kroah.com> Content-Type: text/plain; charset="ISO-8859-1" Cc: kumar.gala@freescale.com, linux-kernel@vger.kernel.org, akpm@kernel.org, linux-console@vger.kernel.org, linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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