From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: USB serial support / Prolific PL2303 Driver Date: Mon, 8 Apr 2013 11:19:28 -0700 Message-ID: <20130408181928.GA7880@kroah.com> References: <20130408150351.GA13824@kroah.com> <1365433602.618685252@f30.mail.ru> <20130408160351.GB12665@kroah.com> <20130408162945.GA26133@kroah.com> <5162FFF5.6040403@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pa0-f48.google.com ([209.85.220.48]:53351 "EHLO mail-pa0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935491Ab3DHSTw (ORCPT ); Mon, 8 Apr 2013 14:19:52 -0400 Received: by mail-pa0-f48.google.com with SMTP id lj1so3376165pab.35 for ; Mon, 08 Apr 2013 11:19:51 -0700 (PDT) Content-Disposition: inline In-Reply-To: <5162FFF5.6040403@gmail.com> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Hans Beckerus Cc: Alexander Shiyan , linux-serial@vger.kernel.org On Mon, Apr 08, 2013 at 07:35:49PM +0200, Hans Beckerus wrote: > >USB starts as one of the last things in the kernel boot process, so the > >best you can ever get is a summary of what happened during the boot, not > >the kernel boot messages as they happen because they happen before the > >USB device is initialized. > Sure. That is an acceptable limitation. However, I wonder if this > will be different once we get U-Boot USB console support on this > platform? > Question though is if Linux ever will be able to benefit from a > first stage driver already being kicked-off by U-Boot. For USB, no, that can't really happen, as the whole USB stack has to be started up "from scratch" after u-boot starts Linux up. There's no way that Linux can take a "already discovered" usb stack and continue it's usage. Unless you possibly use Linux for your bootloader, and if so, in that case, you don't need u-boot, and only do all device discovery once, which is the ideal thing from a speed standpoint. Good luck, greg k-h