Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752544Ab2K1QQm (ORCPT ); Wed, 28 Nov 2012 11:16:42 -0500 Received: from mail-lb0-f174.google.com ([209.85.217.174]:45913 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751154Ab2K1QQk (ORCPT ); Wed, 28 Nov 2012 11:16:40 -0500 MIME-Version: 1.0 In-Reply-To: <20121128060553.GA18166@quad.lixom.net> References: <1354045994-8977-1-git-send-email-dianders@chromium.org> <50B53E37.40303@samsung.com> <18d701cdcd28$74198d70$5c4ca850$%kim@samsung.com> <20121128060553.GA18166@quad.lixom.net> Date: Wed, 28 Nov 2012 08:16:38 -0800 X-Google-Sender-Auth: 8WC7toIX8bB04qU03EEGvPWKFz8 Message-ID: Subject: Re: [PATCH] ARM: EXYNOS: Avoid early use of of_machine_is_compatible() From: Doug Anderson To: Olof Johansson Cc: Kukjin Kim , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, Russell King , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7608 Lines: 203 Olof / Kukjin, On Tue, Nov 27, 2012 at 10:05 PM, Olof Johansson wrote: > On Wed, Nov 28, 2012 at 02:23:09PM +0900, Kukjin Kim wrote: >> Olof Johansson wrote: >> > >> > On Tue, Nov 27, 2012 at 2:27 PM, Kukjin Kim wrote: >> > > On 11/28/12 07:11, Olof Johansson wrote: >> > >> >> > >> On Tue, Nov 27, 2012 at 11:53 AM, Doug Anderson >> > >> wrote: >> > >>> >> > >>> The recent commit "ARM: EXYNOS: add support for EXYNOS5440 SoC" broke >> > >>> support for exynos5250 because of_machine_is_compatible() was used too >> > >>> early in the boot process. It also probably meant that the exynos5440 >> > >>> failed to use the proper iotable. Switch to use >> > >>> of_flat_dt_is_compatible() in both of these cases. >> > >>> >> > >>> The failure I was seeing in exynos5250 because of this was: >> > >>> Division by zero in kernel. >> > >>> [<80015ed4>] (unwind_backtrace+0x0/0xec) from [<8045c7a4>] >> > >>> (dump_stack+0x20/0x24) >> > >>> [<8045c7a4>] (dump_stack+0x20/0x24) from [<80012990>] >> > >>> (__div0+0x20/0x28) >> > >>> [<80012990>] (__div0+0x20/0x28) from [<8021ab04>] >> (Ldiv0_64+0x8/0x18) >> > >>> [<8021ab04>] (Ldiv0_64+0x8/0x18) from [<80068560>] >> > >>> (__clocksource_updatefreq_scale+0x54/0x134) >> > >>> [<80068560>] (__clocksource_updatefreq_scale+0x54/0x134) from >> > >>> [<8006865c>] (__clocksource_register_scale+0x1c/0x54) >> > >>> [<8006865c>] (__clocksource_register_scale+0x1c/0x54) from >> > >>> [<80612a18>] (exynos_timer_init+0x100/0x1e8) >> > >>> [<80612a18>] (exynos_timer_init+0x100/0x1e8) from [<8060d184>] >> > >>> (time_init+0x28/0x38) >> > >>> [<8060d184>] (time_init+0x28/0x38) from [<8060a754>] >> > >>> (start_kernel+0x1e0/0x3c8) >> > >>> [<8060a754>] (start_kernel+0x1e0/0x3c8) from [<40008078>] >> > (0x40008078) >> > >>> >> > >>> Signed-off-by: Doug Anderson >> > >> >> > >> >> > >> Thanks Doug. >> > >> >> > >> Kukjin, I'll apply this directly on top of the previous branch in >> > >> arm-soc, if that's OK with you. >> > >> >> > > Sure, go ahead with my ack if you want, >> > > >> > > Acked-by: Kukjin Kim >> > > >> > > Note, actually there was a fix which uses soc_is_exynos5440() in my >> > local >> > > :-) I'm not sure which one is better at this moment, but I'm OK on this. >> > >> > Ok, applied. Thanks all. >> > >> Olof, just note, happens build error with exynos4_defconfig because of >> non-DT. > > Ick, thanks for catching that. Sorry for this! I will try to be more diligent about trying exynos4_defconfig before submitting future patches to these files. >> >> Following can resolve it or we should create null function for >> of_get_flat_dt_root() and of_flat_dt_is_compatible()... >> >> 8<--------------------------------------- >> From: Kukjin Kim >> Subject: ARM: EXYNOS: fix a build error with non-DT for exynos4 >> >> This fixes following in case of non-DT: >> arch/arm/mach-exynos/common.c: In function 'exynos_init_io': >> arch/arm/mach-exynos/common.c:339: error: implicit declaration of function >> 'of_get_flat_dt_root' >> arch/arm/mach-exynos/common.c:342: error: implicit declaration of function >> 'of_flat_dt_is_compatible' >> make[1]: *** [arch/arm/mach-exynos/common.o] Error 1 >> >> Signed-off-by: Kukjin Kim >> --- >> diff --git a/arch/arm/mach-exynos/common.c b/arch/arm/mach-exynos/common.c >> index b919f5f..2110091 100644 >> --- a/arch/arm/mach-exynos/common.c >> +++ b/arch/arm/mach-exynos/common.c >> @@ -336,12 +336,14 @@ void __init exynos_init_late(void) >> >> void __init exynos_init_io(struct map_desc *mach_desc, int size) >> { >> +#ifdef CONFIG_OF >> unsigned long root = of_get_flat_dt_root(); >> >> /* initialize the io descriptors we need for initialization */ >> if (of_flat_dt_is_compatible(root, "samsung,exynos5440")) >> iotable_init(exynos5440_iodesc, >> ARRAY_SIZE(exynos5440_iodesc)); >> else >> +#endif >> iotable_init(exynos_iodesc, ARRAY_SIZE(exynos_iodesc)); > > I really don't like splitting an if/else with an ifdef like this, it's fragile > code and can be hard to follow. Agree. > There's also a second build error with exynos_defconfig in the > exynos5-dt.c board file due to a missing include. Teaches me to just apply > patches without trying to build. :( In the tree I was testing against (the arm-soc/for-next branch at 659b19ca3a77e2ac32fe84d95242653c75dd07c7) I see the include file in the exynos5-dt.c file already. In my tree it was added by "2eae613b: ARM: EXYNOS: Add MFC device tree support". Your patch applies cleanly on mine but I end up with: #include #include #include #include #include #include > > I'll squash this into Doug's original patch, if that's OK? No objection to squashing a fix and your CL is better than what I have, but see below for an issue. > diff --git a/arch/arm/mach-exynos/common.c b/arch/arm/mach-exynos/common.c > index 796e0c9..77e7c5b 100644 > --- a/arch/arm/mach-exynos/common.c > +++ b/arch/arm/mach-exynos/common.c > @@ -122,6 +122,7 @@ static struct map_desc exynos_iodesc[] __initdata = { > }, > }; > > +#ifdef CONFIG_ARCH_EXYNOS5 Are you sure you want this #ifdef? If so it should match the ifdef used below. With your patch applied I can get a compile error with: make exynos_defconfig echo '# CONFIG_ARCH_EXYNOS5 is not set' >> .config In other words your code will fail if someone wants a FDT-enabled exynos4 build. > static struct map_desc exynos5440_iodesc[] __initdata = { > { > .virtual = (unsigned long)S5P_VA_CHIPID, > @@ -130,6 +131,7 @@ static struct map_desc exynos5440_iodesc[] __initdata = { > .type = MT_DEVICE, > }, > }; > +#endif > > static struct map_desc exynos4_iodesc[] __initdata = { > { > @@ -347,13 +349,19 @@ void __init exynos_init_late(void) > > void __init exynos_init_io(struct map_desc *mach_desc, int size) > { > + struct map_desc *iodesc = exynos_iodesc; > + int iodesc_sz = ARRAY_SIZE(exynos_iodesc); > +#ifdef CONFIG_OF > unsigned long root = of_get_flat_dt_root(); > > /* initialize the io descriptors we need for initialization */ > - if (of_flat_dt_is_compatible(root, "samsung,exynos5440")) > - iotable_init(exynos5440_iodesc, ARRAY_SIZE(exynos5440_iodesc)); > - else > - iotable_init(exynos_iodesc, ARRAY_SIZE(exynos_iodesc)); > + if (of_flat_dt_is_compatible(root, "samsung,exynos5440")) { > + iodesc = exynos5440_iodesc; > + iodesc_sz = ARRAY_SIZE(exynos5440_iodesc); > + } > +#endif > + > + iotable_init(iodesc, iodesc_sz); > > if (mach_desc) > iotable_init(mach_desc, size); > diff --git a/arch/arm/mach-exynos/mach-exynos5-dt.c b/arch/arm/mach-exynos/mach-exynos5-dt.c > index 2a75624..f1326be 100644 > --- a/arch/arm/mach-exynos/mach-exynos5-dt.c > +++ b/arch/arm/mach-exynos/mach-exynos5-dt.c > @@ -10,6 +10,7 @@ > */ > > #include > +#include > #include > > #include > -- 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/