From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 66277884 for ; Thu, 21 Jul 2016 14:21:35 +0000 (UTC) Received: from relay3-d.mail.gandi.net (relay3-d.mail.gandi.net [217.70.183.195]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id F10471CE for ; Thu, 21 Jul 2016 14:21:34 +0000 (UTC) Date: Thu, 21 Jul 2016 07:21:28 -0700 From: Josh Triplett To: David Woodhouse Message-ID: <20160721142127.GA23563@x> References: <20160719034717.GA24189@swordfish> <535ebaec-1653-3077-d17b-feb847fd51d2@suse.com> <578EF192.3050808@huawei.com> <028967b8-6107-9d9c-453a-a7f25e967f70@suse.com> <1469097065.120686.124.camel@infradead.org> <20160721111917.GA20006@x> <1469102358.120686.142.camel@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1469102358.120686.142.camel@infradead.org> Cc: "ksummit-discuss@lists.linuxfoundation.org" Subject: Re: [Ksummit-discuss] [TECH TOPIC] asynchronous printk List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Jul 21, 2016 at 12:59:18PM +0100, David Woodhouse wrote: > On Thu, 2016-07-21 at 04:19 -0700, Josh Triplett wrote: > > I've run into various cases where "console=ttyS0,115200" didn't produce > > any serial output at all, but "earlyprintk=ttyS0,115200,keep" did. > > Note that those are very different things. Because 'ttyS0' for > earlyprintk really means '16x50 UART at 0x3f8'. While the later one > actually depends on it being discovered by the various options we have > for finding them, some of which are only available quite late. Given the discussion in this thread about wanting to eliminate earlyprintk in favor of a unified mechanism that works as early as possible, how would this case work on the system I described above where earlyprintk works and console doesn't? - Josh Triplett