From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Cox Subject: Re: [PATCH v2 1/4] tty: serial: Add 8250 earlycon to support noinit option Date: Mon, 12 Jan 2015 16:08:38 +0000 Message-ID: <1421078918.31978.32.camel@linux.intel.com> References: <1421068104-30463-1-git-send-email-eddie.huang@mediatek.com> <1421068104-30463-2-git-send-email-eddie.huang@mediatek.com> <3712986.8SuKNvhKTk@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <3712986.8SuKNvhKTk@wuerfel> Sender: linux-kernel-owner@vger.kernel.org To: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org, Eddie Huang , Rob Herring , Mark Rutland , Greg Kroah-Hartman , Matthias Brugger , devicetree@vger.kernel.org, Vladimir Murzin , srv_heupstream@mediatek.com, Pawel Moll , Ian Campbell , Catalin Marinas , Jonathan Corbet , Will Deacon , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, yh.chen@mediatek.com, Howard Chen , Ashwin Chaugule , linux-serial@vger.kernel.org, Kumar Gala , "Joe.C" , Jiri Slaby List-Id: devicetree@vger.kernel.org On Mon, 2015-01-12 at 16:35 +0100, Arnd Bergmann wrote: > On Monday 12 January 2015 21:08:21 Eddie Huang wrote: > > Add earlycon support not only baudrate option, but also add noinit option. > > If use noinit option, 8250 earlycon will not init serial hardware and use > > loader setting. > > > > Signed-off-by: Eddie Huang > > I probably missed something in the previous discussion, but why is > "noinit" not just the default? I believe that is how we handle early > serial ports on PowerPC, and I see no downsides to it. Most PC hardware at least needs the port initialised to use it. It won't have been configured by the firmware in many cases. Alan