From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <522437E8.1050604@atmel.com> Date: Mon, 2 Sep 2013 15:02:00 +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> In-Reply-To: <20130831170422.GA21617@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 9/1/2013 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. So please sent them out. ;) Best Regards, Josh Wu