Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756992AbcCaRGs (ORCPT ); Thu, 31 Mar 2016 13:06:48 -0400 Received: from mail-lb0-f169.google.com ([209.85.217.169]:35278 "EHLO mail-lb0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753348AbcCaRGn (ORCPT ); Thu, 31 Mar 2016 13:06:43 -0400 Subject: Re: [PATCH v7 1/5] of/serial: move earlycon early_param handling to serial To: Greg Kroah-Hartman References: <1459431629-27934-1-git-send-email-aleksey.makarov@linaro.org> <1459431629-27934-2-git-send-email-aleksey.makarov@linaro.org> <20160331163203.GC10256@kroah.com> Cc: Russell King , linux-serial@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, "Rafael J . Wysocki" , Len Brown , Leif Lindholm , Graeme Gregory , Al Stone , Christopher Covington , Yury Norov , Peter Hurley , Andy Shevchenko , "Zheng, Lv" , Rob Herring , Frank Rowand , Grant Likely , Jiri Slaby , devicetree@vger.kernel.org From: Aleksey Makarov Message-ID: <56FD5894.3060105@linaro.org> Date: Thu, 31 Mar 2016 20:04:20 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.0 MIME-Version: 1.0 In-Reply-To: <20160331163203.GC10256@kroah.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3903 Lines: 112 On 03/31/2016 07:32 PM, Greg Kroah-Hartman wrote: > On Thu, Mar 31, 2016 at 04:40:23PM +0300, Aleksey Makarov wrote: >> From: Leif Lindholm >> >> We have multiple "earlycon" early_param handlers - merge the DT one into >> the main earlycon one. It's a cleanup that also will be useful >> to defer setting up DT console until ACPI/DT decision is made. >> >> Rename the exported function to avoid clashing with the function from >> arch/microblaze/kernel/prom.c >> >> Signed-off-by: Leif Lindholm >> Signed-off-by: Aleksey Makarov >> Acked-by: Rob Herring >> --- >> drivers/of/fdt.c | 11 +---------- >> drivers/tty/serial/earlycon.c | 2 +- >> include/linux/of_fdt.h | 2 ++ >> 3 files changed, 4 insertions(+), 11 deletions(-) >> >> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c >> index 3349d2a..b50f775 100644 >> --- a/drivers/of/fdt.c >> +++ b/drivers/of/fdt.c >> @@ -805,7 +805,7 @@ static inline void early_init_dt_check_for_initrd(unsigned long node) >> >> #ifdef CONFIG_SERIAL_EARLYCON >> >> -static int __init early_init_dt_scan_chosen_serial(void) >> +int __init early_init_dt_scan_chosen_stdout(void) >> { >> int offset; >> const char *p, *q, *options = NULL; >> @@ -849,15 +849,6 @@ static int __init early_init_dt_scan_chosen_serial(void) >> } >> return -ENODEV; >> } >> - >> -static int __init setup_of_earlycon(char *buf) >> -{ >> - if (buf) >> - return 0; >> - >> - return early_init_dt_scan_chosen_serial(); >> -} >> -early_param("earlycon", setup_of_earlycon); >> #endif >> >> /** >> diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c >> index 067783f..7aae655 100644 >> --- a/drivers/tty/serial/earlycon.c >> +++ b/drivers/tty/serial/earlycon.c >> @@ -209,7 +209,7 @@ static int __init param_setup_earlycon(char *buf) >> * don't generate a warning from parse_early_params() in that case >> */ >> if (!buf || !buf[0]) >> - return 0; >> + return early_init_dt_scan_chosen_stdout(); >> >> err = setup_earlycon(buf); >> if (err == -ENOENT || err == -EALREADY) >> diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h >> index 2fbe868..5cfe322 100644 >> --- a/include/linux/of_fdt.h >> +++ b/include/linux/of_fdt.h >> @@ -63,6 +63,7 @@ extern int early_init_dt_scan_chosen(unsigned long node, const char *uname, >> int depth, void *data); >> extern int early_init_dt_scan_memory(unsigned long node, const char *uname, >> int depth, void *data); >> +extern int early_init_dt_scan_chosen_stdout(void); >> extern void early_init_fdt_scan_reserved_mem(void); >> extern void early_init_fdt_reserve_self(void); >> extern void early_init_dt_add_memory_arch(u64 base, u64 size); >> @@ -91,6 +92,7 @@ extern void early_get_first_memblock_info(void *, phys_addr_t *); >> extern u64 of_flat_dt_translate_address(unsigned long node); >> extern void of_fdt_limit_memory(int limit); >> #else /* CONFIG_OF_FLATTREE */ >> +static inline int early_init_dt_scan_chosen_stdout(void) { return -ENODEV; } > > Doesn't this change the default logic? Today you are returning 0 if you > don't have this config option set, I am not sure I understand this. Which return value do you mean? 1. early_init_dt_scan_chosen_stdout() Today if CONFIG_OF_FLATTREE is not set then early_init_dt_scan_chosen_stdout() does not exist. 2. param_setup_earlycon() Today we have 2 handlers for "earlycon" option. One (in fdt.c) is for the option without args, and another (earlycon.c) always expects agrs. But both return 0 for the opposite cases becasue they can not check what another hander returns. Now we have just one handler and it can return correct value. > and now you return -ENODEV, did you > test this out? Yes, I tested it. Thank you Aleksey Makarov > > thanks, > > greg k-h >