Re: [PATCH v2 2/7] mfd: Add ST Multi-Function eXpander (STMFX) core driver

From: kbuild test robot
Date: Fri Sep 21 2018 - 02:30:51 EST


Hi Amelie,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on ljones-mfd/for-mfd-next]
[also build test WARNING on v4.19-rc4 next-20180920]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url: https://github.com/0day-ci/linux/commits/Amelie-Delaunay/dt-bindings-mfd-Add-ST-Multi-Function-eXpander-STMFX-core-bindings/20180920-185854
base: https://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd.git for-mfd-next
config: i386-allmodconfig (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=i386

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/mfd/stmfx.c: In function 'stmfx_function_enable':
>> drivers/mfd/stmfx.c:103:8: warning: 'mask' may be used uninitialized in this function [-Wmaybe-uninitialized]
mask |= STMFX_REG_SYS_CTRL_GPIO_EN;
drivers/mfd/stmfx.c:100:5: note: 'mask' was declared here
u8 mask;
^~~~
drivers/mfd/stmfx.c: In function 'stmfx_function_disable':
>> drivers/mfd/stmfx.c:103:8: warning: 'mask' may be used uninitialized in this function [-Wmaybe-uninitialized]
mask |= STMFX_REG_SYS_CTRL_GPIO_EN;
drivers/mfd/stmfx.c:100:5: note: 'mask' was declared here
u8 mask;
^~~~

vim +/mask +103 drivers/mfd/stmfx.c

97
98 static u8 stmfx_func_to_mask(u32 func)
99 {
100 u8 mask;
101
102 if (func & STMFX_FUNC_GPIO)
> 103 mask |= STMFX_REG_SYS_CTRL_GPIO_EN;
104
105 if ((func & STMFX_FUNC_ALTGPIO_LOW) || (func & STMFX_FUNC_ALTGPIO_HIGH))
106 mask |= STMFX_REG_SYS_CTRL_ALTGPIO_EN;
107
108 if (func & STMFX_FUNC_TS)
109 mask |= STMFX_REG_SYS_CTRL_TS_EN;
110
111 if (func & STMFX_FUNC_IDD)
112 mask |= STMFX_REG_SYS_CTRL_IDD_EN;
113
114 return mask;
115 }
116

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