Re: [PATCH] spi: kconfig: When possible, compile drivers with COMPILE_TEST
From: Geert Uytterhoeven
Date: Fri Oct 16 2015 - 03:27:34 EST
On Fri, Oct 16, 2015 at 2:30 AM, kbuild test robot <lkp@xxxxxxxxx> wrote:
> [auto build test WARNING on spi/for-next -- if it's inappropriate base, please suggest rules for selecting the more suitable base]
>
> url: https://github.com/0day-ci/linux/commits/Luis-de-Bethencourt/spi-kconfig-When-possible-compile-drivers-with-COMPILE_TEST/20151015-014349
> config: openrisc-allyesconfig (attached as .config)
> reproduce:
> wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # save the attached .config to linux build tree
> make.cross ARCH=openrisc
>
> Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
> http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings
>
> All warnings (new ones prefixed by >>):
>
> drivers/spi/spi-davinci.c: In function 'davinci_spi_chipselect':
>>> drivers/spi/spi-davinci.c:219:6: warning: 'gpio' may be used uninitialized in this function
That's a false positive...
> vim +/gpio +219 drivers/spi/spi-davinci.c
>
> 358934a6 drivers/spi/davinci_spi.c Sandeep Paulraj 2009-12-16 203
> 358934a6 drivers/spi/davinci_spi.c Sandeep Paulraj 2009-12-16 204 v &= ~bits;
> 358934a6 drivers/spi/davinci_spi.c Sandeep Paulraj 2009-12-16 205 iowrite32(v, addr);
> 358934a6 drivers/spi/davinci_spi.c Sandeep Paulraj 2009-12-16 206 }
> 358934a6 drivers/spi/davinci_spi.c Sandeep Paulraj 2009-12-16 207
> 358934a6 drivers/spi/davinci_spi.c Sandeep Paulraj 2009-12-16 208 /*
> 358934a6 drivers/spi/davinci_spi.c Sandeep Paulraj 2009-12-16 209 * Interface to control the chip select signal
> 358934a6 drivers/spi/davinci_spi.c Sandeep Paulraj 2009-12-16 210 */
> 358934a6 drivers/spi/davinci_spi.c Sandeep Paulraj 2009-12-16 211 static void davinci_spi_chipselect(struct spi_device *spi, int value)
> 358934a6 drivers/spi/davinci_spi.c Sandeep Paulraj 2009-12-16 212 {
> 212d4b69 drivers/spi/davinci_spi.c Sekhar Nori 2010-10-11 213 struct davinci_spi *dspi;
> 358934a6 drivers/spi/davinci_spi.c Sandeep Paulraj 2009-12-16 214 struct davinci_spi_platform_data *pdata;
> 365a7bb3 drivers/spi/spi-davinci.c Murali Karicheri 2014-09-16 215 struct davinci_spi_config *spicfg = spi->controller_data;
> 7978b8c3 drivers/spi/davinci_spi.c Brian Niebuhr 2010-08-13 216 u8 chip_sel = spi->chip_select;
> 212d4b69 drivers/spi/davinci_spi.c Sekhar Nori 2010-10-11 217 u16 spidat1 = CS_DEFAULT;
> 23853973 drivers/spi/davinci_spi.c Brian Niebuhr 2010-08-13 218 bool gpio_chipsel = false;
> a88e34ea drivers/spi/spi-davinci.c Murali Karicheri 2014-08-01 @219 int gpio;
> 358934a6 drivers/spi/davinci_spi.c Sandeep Paulraj 2009-12-16 220
> 212d4b69 drivers/spi/davinci_spi.c Sekhar Nori 2010-10-11 221 dspi = spi_master_get_devdata(spi->master);
> aae7147d drivers/spi/spi-davinci.c Murali Karicheri 2012-12-11 222 pdata = &dspi->pdata;
> 358934a6 drivers/spi/davinci_spi.c Sandeep Paulraj 2009-12-16 223
> c0600140 drivers/spi/spi-davinci.c Grygorii Strashko 2014-08-01 224 if (spi->cs_gpio >= 0) {
> a88e34ea drivers/spi/spi-davinci.c Murali Karicheri 2014-08-01 225 /* SPI core parse and update master->cs_gpio */
> 23853973 drivers/spi/davinci_spi.c Brian Niebuhr 2010-08-13 226 gpio_chipsel = true;
> a88e34ea drivers/spi/spi-davinci.c Murali Karicheri 2014-08-01 227 gpio = spi->cs_gpio;
... which can be avoided by removing the variables gpio_chipsel and gpio,
and replacing gpio_chipsel by "spi->cs_gpio >= 0", and gpio by "spi->cs_gpio".
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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