From mboxrd@z Thu Jan 1 00:00:00 1970 From: ezequiel.garcia@free-electrons.com (Ezequiel Garcia) Date: Mon, 2 Sep 2013 14:13:24 -0300 Subject: [PATCH] mtd: atmel_nand: fix the warning when CONFIG_OF is not defined In-Reply-To: <522437E8.1050604@atmel.com> 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> Message-ID: <20130902171323.GA28419@localhost> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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? -- Ezequiel Garc?a, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com