From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <52255E32.6040009@atmel.com> Date: Tue, 3 Sep 2013 11:57:38 +0800 From: Josh Wu MIME-Version: 1.0 To: Ezequiel Garcia Subject: Re: [PATCH] mtd: atmel_nand: fix the warning when CONFIG_OF is not defined References: <1375846569-9499-1-git-send-email-josh.wu@atmel.com> <1377894233.22372.86.camel@shinybook.infradead.org> <20130831170422.GA21617@localhost> <522437E8.1050604@atmel.com> <20130902171323.GA28419@localhost> In-Reply-To: <20130902171323.GA28419@localhost> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit Cc: dedekind1@gmail.com, David Woodhouse , nicolas.ferre@atmel.com, linux-mtd@lists.infradead.org, computersforpeace@gmail.com, plagnioj@jcrosoft.com, linux-arm-kernel@lists.infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi, Ezequiel On 9/3/2013 1:13 AM, Ezequiel Garcia wrote: > On Mon, Sep 02, 2013 at 03:02:00PM +0800, Josh Wu wrote: >> Hi, Ezequiel >> >> On 9/1/2013 1:04 AM, Ezequiel Garcia wrote: >>> On Fri, Aug 30, 2013 at 09:23:53PM +0100, David Woodhouse wrote: >>>> On Wed, 2013-08-07 at 11:36 +0800, Josh Wu wrote: >>>>> This patch fix following warning: >>>>> >>>>> drivers/mtd/nand/atmel_nand.c:2007: warning: 'atmel_nand_nfc_match' defined but not used >>>>> >>>>> This patch add '#if defined(CONFIG_OF)' block to guard around the definition of >>>>> atmel_nand_nfc_match, in order to avoid the warning when kernel is configurated >>>>> as non-dt supported. >>>> Ick. This driver is littered with CONFIG_OF checks. Yet I've just seen a >>>> patch to pxa3xx_nand which *removes* ifdefs, on the basis that all the >>>> of_match_ functions/macros will just 'do the right thing'. Can't we do >>>> that here too? We might just need to add __maybe_unused? >>>> >>> We can. We just need to provide a few dummy functions in linux/of_mtd.h >>> just like the other of_xxx() are doing. See below! >>> >>>>> +#if defined(CONFIG_OF) >>>>> static struct of_device_id atmel_nand_nfc_match[] = { >>>>> { .compatible = "atmel,sama5d3-nfc" }, >>>>> { /* sentinel */ } >>>>> }; >>>>> +#endif >>>> Also, why doesn't this one appear in a MODULE_DEVICE_TABLE() ? >>>> >>> Indeed. And why doesn't it have a "const" keyword? >> Thanks to point these out. >> >>> So, in order to remove the CONFIG_OF safely from this driver, >>> and avoid any stupid warnings, we need to first implement >>> these dummies: >>> >>> --------------------------------8<----------------------------------- >>> diff --git a/include/linux/of_mtd.h b/include/linux/of_mtd.h >>> index ed7f267..66f173e 100644 >>> --- a/include/linux/of_mtd.h >>> +++ b/include/linux/of_mtd.h >>> @@ -14,6 +14,21 @@ >>> int of_get_nand_ecc_mode(struct device_node *np); >>> int of_get_nand_bus_width(struct device_node *np); >>> bool of_get_nand_on_flash_bbt(struct device_node *np); >>> +#else >>> +static inline int of_get_nand_ecc_mode(struct device_node *np) >>> +{ >>> + return -ENOSYS; >>> +} >>> + >>> +static inline int of_get_nand_bus_width(struct device_node *np) >>> +{ >>> + return -ENOSYS; >>> +} >>> + >>> +static inline bool of_get_nand_on_flash_bbt(struct device_node *np) >>> +{ >>> + return false; >>> +} >>> #endif >>> >>> #endif /* __LINUX_OF_MTD_H */ >>> -------------------------------->8----------------------------------- >>> >>> And then, with this little patch, we get rid of the ugly CONFIG_OF check >>> from the atmel_nand driver: >>> >>> --------------------------------8<----------------------------------- >>> diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c >>> index 0e365da..ac58098 100644 >>> --- a/drivers/mtd/nand/atmel_nand.c >>> +++ b/drivers/mtd/nand/atmel_nand.c >>> @@ -1448,7 +1448,6 @@ static void atmel_nand_hwctl(struct mtd_info *mtd, int mode) >>> ecc_writel(host->ecc, CR, ATMEL_ECC_RST); >>> } >>> >>> -#if defined(CONFIG_OF) >>> static int atmel_of_init_port(struct atmel_nand_host *host, >>> struct device_node *np) >>> { >>> @@ -1456,7 +1455,7 @@ static int atmel_of_init_port(struct atmel_nand_host *host, >>> u32 offset[2]; >>> int ecc_mode; >>> struct atmel_nand_data *board = &host->board; >>> - enum of_gpio_flags flags; >>> + enum of_gpio_flags flags = 0; >>> >>> if (of_property_read_u32(np, "atmel,nand-addr-offset", &val) == 0) { >>> if (val >= 32) { >>> @@ -1539,13 +1538,6 @@ static int atmel_of_init_port(struct atmel_nand_host *host, >>> >>> return 0; >>> } >>> -#else >>> -static int atmel_of_init_port(struct atmel_nand_host *host, >>> - struct device_node *np) >>> -{ >>> - return -EINVAL; >>> -} >>> -#endif >>> >>> static int __init atmel_hw_nand_init_params(struct platform_device *pdev, >>> struct atmel_nand_host *host) >>> @@ -2205,14 +2197,12 @@ static int __exit atmel_nand_remove(struct platform_device *pdev) >>> return 0; >>> } >>> >>> -#if defined(CONFIG_OF) >>> static const struct of_device_id atmel_nand_dt_ids[] = { >>> { .compatible = "atmel,at91rm9200-nand" }, >>> { /* sentinel */ } >>> }; >>> >>> MODULE_DEVICE_TABLE(of, atmel_nand_dt_ids); >>> -#endif >>> >>> static int atmel_nand_nfc_probe(struct platform_device *pdev) >>> { >>> @@ -2251,12 +2241,11 @@ static int atmel_nand_nfc_probe(struct platform_device *pdev) >>> return 0; >>> } >>> >>> -#if defined(CONFIG_OF) >>> -static struct of_device_id atmel_nand_nfc_match[] = { >>> +static const struct of_device_id atmel_nand_nfc_match[] = { >>> { .compatible = "atmel,sama5d3-nfc" }, >>> { /* sentinel */ } >>> }; >>> -#endif >>> +MODULE_DEVICE_TABLE(of, atmel_nand_nfc_match); >>> >>> static struct platform_driver atmel_nand_nfc_driver = { >>> .driver = { >>> -------------------------------->8----------------------------------- >>> >>> Of course, these are untested. If they look OK and don't cause any trouble, >>> then I'll prepare proper patches. >> Looks nice to me. Your proposal patch does the right thing to remove the >> CONFIG_OF. > Great! > >> So please sent them out. ;) >> > I'm a bit short on time these days, how about I send the first one > for the stub !OF addition and on top of that you send the atmel > patches? Okay. Best Regards, Josh Wu