Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757952Ab3FAD7d (ORCPT ); Fri, 31 May 2013 23:59:33 -0400 Received: from mail-pa0-f41.google.com ([209.85.220.41]:47273 "EHLO mail-pa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755270Ab3FAD72 (ORCPT ); Fri, 31 May 2013 23:59:28 -0400 Date: Fri, 31 May 2013 20:59:29 -0700 From: Olof Johansson To: Tushar Behera Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, arnd@arndb.de, kgene.kim@samsung.com, patches@linaro.org Subject: Re: [PATCH 1/3] ARM: EXYNOS: uncompress - print debug messages if DEBUG_LL is defined Message-ID: <20130601035929.GA3868@quad.lixom.net> References: <1370000944-19786-1-git-send-email-tushar.behera@linaro.org> <1370000944-19786-2-git-send-email-tushar.behera@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1370000944-19786-2-git-send-email-tushar.behera@linaro.org> 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: 2406 Lines: 59 On Fri, May 31, 2013 at 05:19:02PM +0530, Tushar Behera wrote: > Printing low-level debug messages make an assumption that the specified > UART port has been preconfigured by the bootloader. Incorrectly > specified UART port results in system getting stalled while printing the > message "Uncompressing Linux... done, booting the kernel" > > This UART port number is specified through S3C_LOWLEVEL_UART_PORT. Since > the UART port might different for different board, it is not possible to > specify it correctly for every board that use a common defconfig file. > > Calling this print subroutine only when DEBUG_LL fixes the problem. By > disabling DEBUG_LL in default config file, we would be able to boot > multiple boards with different default UART ports. > > With this current approach, we miss the print "Uncompressing Linux... > done, booting the kernel." when DEBUG_LL is not defined. > > Signed-off-by: Tushar Behera > --- > arch/arm/mach-exynos/include/mach/uncompress.h | 11 ++++++++--- > arch/arm/plat-samsung/include/plat/uncompress.h | 10 +++++++++- > 2 files changed, 17 insertions(+), 4 deletions(-) > > diff --git a/arch/arm/mach-exynos/include/mach/uncompress.h b/arch/arm/mach-exynos/include/mach/uncompress.h > index 2979995..730f69f 100644 > --- a/arch/arm/mach-exynos/include/mach/uncompress.h > +++ b/arch/arm/mach-exynos/include/mach/uncompress.h > @@ -37,11 +37,16 @@ static void arch_detect_cpu(void) > chip_id >>= 20; > chip_id &= 0xf; > > +#ifdef CONFIG_DEBUG_LL > if (chip_id == 0x5) > - uart_base = (volatile u8 *)EXYNOS5_PA_UART + (S3C_UART_OFFSET * CONFIG_S3C_LOWLEVEL_UART_PORT); > + uart_base = (volatile u8 *)EXYNOS5_PA_UART + > + (S3C_UART_OFFSET * CONFIG_S3C_LOWLEVEL_UART_PORT); > else > - uart_base = (volatile u8 *)EXYNOS4_PA_UART + (S3C_UART_OFFSET * CONFIG_S3C_LOWLEVEL_UART_PORT); > - > + uart_base = (volatile u8 *)EXYNOS4_PA_UART + > + (S3C_UART_OFFSET * CONFIG_S3C_LOWLEVEL_UART_PORT); > +#else > + uart_base = NULL; > +#endif You can do: if (!config_enabled(CONFIG_DEBUG_LL)) return; Since uart_base will be set to 0 by being in BSS anyway. -Olof -- 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/