From mboxrd@z Thu Jan 1 00:00:00 1970 From: Feng Tang Subject: Re: [PATCH 2/5] hsu, earlyprintk: add early printk for hsu_port2 console Date: Tue, 7 Sep 2010 09:28:53 +0800 Message-ID: <20100907092853.1aa1aa24@feng-i7> References: <20100906123843.1328.3930.stgit@localhost.localdomain> <20100906123908.1328.3598.stgit@localhost.localdomain> <20100906141746.GB29291@elte.hu> <20100906151542.2b155adf@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: Received: from mga02.intel.com ([134.134.136.20]:11755 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755070Ab0IGBJM (ORCPT ); Mon, 6 Sep 2010 21:09:12 -0400 In-Reply-To: <20100906151542.2b155adf@linux.intel.com> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Alan Cox Cc: Ingo Molnar , "linux-serial@vger.kernel.org" , "greg@kroah.com" , the arch/x86 maintainers On Mon, 6 Sep 2010 22:15:42 +0800 Alan Cox wrote: > > > > + /* GPIO workaround */ > > > + set_fixmap_nocache(FIX_EARLYCON_MEM_BASE, > > > MFD_GPIO_HSU_REG); > > > + phsu = (void *)(__fix_to_virt(FIX_EARLYCON_MEM_BASE) + > > > + (MFD_GPIO_HSU_REG & (PAGE_SIZE - 1))); > > > + > > > + *((u32 *)phsu) = 0x55465; > > > > What does 0x55465 stand for? > > It's a firmware fixup. Its a magic value (even to most of us who work > here ;)). Feng - am I right in thinking we don't need that anyway with > the current firmware ? Yes, it's a fixup for firmware, it set GPIO controller's register to correctly configure the GPIO lines used by HSU. Latest firmware already fix that, and it could be removed. Thank you both for the comments, will try to address them and make a v2. Thanks, Feng