From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cantor2.suse.de ([195.135.220.15]:50680 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753298AbaCaOfp (ORCPT ); Mon, 31 Mar 2014 10:35:45 -0400 Date: Mon, 31 Mar 2014 16:35:43 +0200 From: Michal Marek Subject: Re: [mtd/sbc_gxx] kernel BUG at include/linux/mtd/map.h:148! Message-ID: <20140331143543.GA9764@sepie.suse.cz> References: <20140327140140.GA9083@localhost> <20140331113412.GA13548@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140331113412.GA13548@localhost> Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Fengguang Wu Cc: Bjorn Helgaas , "linux-mtd@lists.infradead.org" , LKML , David Woodhouse , Brian Norris , linux-kbuild On Mon, Mar 31, 2014 at 07:34:12PM +0800, Fengguang Wu wrote: > CC Michal and kbuild list. > > On Thu, Mar 27, 2014 at 04:51:53PM -0600, Bjorn Helgaas wrote: > > [+cc David, Brian] > > > > On Thu, Mar 27, 2014 at 8:01 AM, Fengguang Wu wrote: > > > FYI, here is a very old warning, too old to be bisected. > > > > > > [ 5.282127] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, supports DPO and FUA > > > [ 5.286079] SBC-GXx flash: IO:0x258-0x259 MEM:0xdc000-0xdffff > > > [ 5.288723] ------------[ cut here ]------------ > > > [ 5.289649] kernel BUG at include/linux/mtd/map.h:148! > > > > I think the problem is that your randconfig happens to have none of > > CONFIG_MTD_MAP_BANK_WIDTH_* set (you should have played the lottery > > today!), and the default implementation of map_bankwidth() in that > > case is just "BUG()": > > > > $ grep MTD_MAP config-3.14.0-rc8-wl-03045-gdf16ea4 > > # CONFIG_MTD_MAP_BANK_WIDTH_1 is not set > > # CONFIG_MTD_MAP_BANK_WIDTH_2 is not set > > # CONFIG_MTD_MAP_BANK_WIDTH_4 is not set > > # CONFIG_MTD_MAP_BANK_WIDTH_8 is not set > > # CONFIG_MTD_MAP_BANK_WIDTH_16 is not set > > # CONFIG_MTD_MAP_BANK_WIDTH_32 is not set > > > > I don't know enough Kconfig or MTD to fix this. > > Michal, the problem we run into is, how to select one of the above > CONFIG_MTD_MAP_BANK_WIDTH_xx in "make randconfig". You can't enforce this in Kconfig. What you can do is to make the logic more fool-proof and fall back to some sensible default if none of the CONFIG_MTD_MAP_BANK_WIDTH_* options is enabled. Like this >From 76e66ceea7e2ffbb1d39c01af2eaf6f2b66c2be3 Mon Sep 17 00:00:00 2001 From: Michal Marek Date: Mon, 31 Mar 2014 16:25:32 +0200 Subject: [PATCH] mtd: Fall back to MTD_MAP_BANK_WIDTH_1 if none is specified This is mainly to fix make randconfig errors. Signed-off-by: Michal Marek --- drivers/mtd/chips/Kconfig | 8 ++++++++ include/linux/mtd/map.h | 4 ++-- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/mtd/chips/Kconfig b/drivers/mtd/chips/Kconfig index e4696b3..219de49 100644 --- a/drivers/mtd/chips/Kconfig +++ b/drivers/mtd/chips/Kconfig @@ -115,6 +115,14 @@ config MTD_MAP_BANK_WIDTH_32 If you wish to support CFI devices on a physical bus which is 256 bits wide, say 'Y'. +config HAVE_MTD_MAP_BANK_WIDTH_1 + bool + default MTD_MAP_BANK_WIDTH_1 || (!MTD_MAP_BANK_WIDTH_2 && !MTD_MAP_BANK_WIDTH_4 && !MTD_MAP_BANK_WIDTH_8 && !MTD_MAP_BANK_WIDTH_16 && !MTD_MAP_BANK_WIDTH_32) + +if HAVE_MTD_MAP_BANK_WIDTH_1 && !MTD_MAP_BANK_WIDTH_1 +comment "no buswidth selected, using 8-bit as a fallback " +endif + config MTD_CFI_I1 bool "Support 1-chip flash interleave" if MTD_CFI_GEOMETRY default y diff --git a/include/linux/mtd/map.h b/include/linux/mtd/map.h index 5f487d7..d4f4f49 100644 --- a/include/linux/mtd/map.h +++ b/include/linux/mtd/map.h @@ -32,7 +32,7 @@ #include #include -#ifdef CONFIG_MTD_MAP_BANK_WIDTH_1 +#ifdef CONFIG_HAVE_MTD_MAP_BANK_WIDTH_1 #define map_bankwidth(map) 1 #define map_bankwidth_is_1(map) (map_bankwidth(map) == 1) #define map_bankwidth_is_large(map) (0) @@ -156,7 +156,7 @@ static inline int map_bankwidth(void *map) static inline int map_bankwidth_supported(int w) { switch (w) { -#ifdef CONFIG_MTD_MAP_BANK_WIDTH_1 +#ifdef CONFIG_HAVE_MTD_MAP_BANK_WIDTH_1 case 1: #endif #ifdef CONFIG_MTD_MAP_BANK_WIDTH_2 -- 1.8.4.5