Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031324AbbKDSxr (ORCPT ); Wed, 4 Nov 2015 13:53:47 -0500 Received: from mail-pa0-f41.google.com ([209.85.220.41]:33167 "EHLO mail-pa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756377AbbKDSxp (ORCPT ); Wed, 4 Nov 2015 13:53:45 -0500 Date: Wed, 4 Nov 2015 10:53:41 -0800 From: Brian Norris To: =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= Cc: Javier Martinez Canillas , Linux Kernel Mailing List , Fengguang Wu , Michael Ellerman , Luis de Bethencourt , Jeremy Kerr , Neelesh Gupta , "linux-mtd@lists.infradead.org" , David Woodhouse , Cyril Bur Subject: Re: [PATCH] mtd: Make MTD_BCM47XXSFLASH to depend on MIPS Message-ID: <20151104185341.GN7274@google.com> References: <1444813494-14985-1-git-send-email-javier@osg.samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1896 Lines: 39 On Wed, Nov 04, 2015 at 10:04:26AM +0100, Rafał Miłecki wrote: > On 14 October 2015 at 11:04, Javier Martinez Canillas > wrote: > > The bcm47xxsflash driver uses the KSEG0ADDR() function to map an address > > to a certain kernel segment. But that is only defined if the MIPS config > > symbol is enabled. The driver does not have an explicit dependency on it > > and relies on a transitive dependency relation: > > > > MTD_BCM47XXSFLASH -> BCMA_SFLASH -> BCMA_DRIVER_MIPS -> BCMA && MIPS > > > > But BCMA_SFLASH and BCMA_DRIVER_MIPS have only runtime and not buildtime > > dependency with MIPS so can be changed to be built test using the config > > COMPILE_TEST symbol. But that would make MTD_BCM47XXSFLASH be built with > > MIPS not enabled and cause the following build error: > > > > drivers/mtd/devices//bcm47xxsflash.c: In function 'bcm47xxsflash_read': > > drivers/mtd/devices//bcm47xxsflash.c:112:2: error: implicit declaration of function 'KSEG0ADDR' [-Werror=implicit-function-declaration] > > memcpy_fromio(buf, (void __iomem *)KSEG0ADDR(b47s->window + from), > > I think we're not really supposed to use KSEG0ADDR anyway. What about > replacing it with ioremap_nocache? I'm not really a MIPS expert, but isn't KSEG0 actually *cached*? (And is that correct, then?) AIUI, ioremap_nocache() will actually get you a KSEG1 address here, I think. Also (a bit of a tangent) couldn't "window" be better passed as a second resource by drivers/bcma/driver_chipcommon_sflash.c? Seems like that would fit the device/resource model better, and then you wouldn't have to do any __iomem casts in bcm47xxsflash.c. Brian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/