[nbd168-wireless:mt76 5/28] drivers/net/wireless/mediatek/mt76/mt7915/dma.c:97:6: warning: variable 'base' is used uninitialized whenever 'if' condition is false
From: kernel test robot
Date: Wed Dec 22 2021 - 18:26:09 EST
tree: https://github.com/nbd168/wireless mt76
head: 05f0500c7b0147353e97de7369d504c5fbd3951e
commit: 22c2fb9495d35e0c442c23bcd3b8a4a18a28c62d [5/28] mt76: mt7915: rework dma.c to adapt mt7916 changes
config: mips-randconfig-r033-20211222 (https://download.01.org/0day-ci/archive/20211223/202112230704.dKCp3lmX-lkp@xxxxxxxxx/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project de4e0195ae1c39f1c3b07834b8e32c113f4f20eb)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install mips cross compiling tool for clang build
# apt-get install binutils-mips-linux-gnu
# https://github.com/nbd168/wireless/commit/22c2fb9495d35e0c442c23bcd3b8a4a18a28c62d
git remote add nbd168-wireless https://github.com/nbd168/wireless
git fetch --no-tags nbd168-wireless mt76
git checkout 22c2fb9495d35e0c442c23bcd3b8a4a18a28c62d
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash drivers/net/wireless/mediatek/mt76/mt7915/
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>
All warnings (new ones prefixed by >>):
>> drivers/net/wireless/mediatek/mt76/mt7915/dma.c:97:6: warning: variable 'base' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
if (!is_mt7915(&dev->mt76)) {
^~~~~~~~~~~~~~~~~~~~~~
drivers/net/wireless/mediatek/mt76/mt7915/dma.c:101:70: note: uninitialized use occurs here
mt76_wr(dev, MT_RXQ_EXT_CTRL(MT_RXQ_EXT_WA) + ofs, PREFETCH(0x1c0 + base, 0x4));
^~~~
drivers/net/wireless/mediatek/mt76/mt7915/dma.c:85:35: note: expanded from macro 'PREFETCH'
#define PREFETCH(_base, _depth) ((_base) << 16 | (_depth))
^~~~~
drivers/net/wireless/mediatek/mt76/mt7915/../mt76.h:829:63: note: expanded from macro 'mt76_wr'
#define mt76_wr(dev, ...) (dev)->mt76.bus->wr(&((dev)->mt76), __VA_ARGS__)
^~~~~~~~~~~
drivers/net/wireless/mediatek/mt76/mt7915/dma.c:97:2: note: remove the 'if' if its condition is always true
if (!is_mt7915(&dev->mt76)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/wireless/mediatek/mt76/mt7915/dma.c:86:10: note: initialize the variable 'base' to silence this warning
u32 base;
^
= 0
1 warning generated.
vim +97 drivers/net/wireless/mediatek/mt76/mt7915/dma.c
82
83 static void __mt7915_dma_prefetch(struct mt7915_dev *dev, u32 ofs)
84 {
85 #define PREFETCH(_base, _depth) ((_base) << 16 | (_depth))
86 u32 base;
87
88 /* prefetch SRAM wrapping boundary for tx/rx ring. */
89 mt76_wr(dev, MT_MCUQ_EXT_CTRL(MT_MCUQ_FWDL) + ofs, PREFETCH(0x0, 0x4));
90 mt76_wr(dev, MT_MCUQ_EXT_CTRL(MT_MCUQ_WM) + ofs, PREFETCH(0x40, 0x4));
91 mt76_wr(dev, MT_TXQ_EXT_CTRL(0) + ofs, PREFETCH(0x80, 0x4));
92 mt76_wr(dev, MT_TXQ_EXT_CTRL(1) + ofs, PREFETCH(0xc0, 0x4));
93 mt76_wr(dev, MT_MCUQ_EXT_CTRL(MT_MCUQ_WA) + ofs, PREFETCH(0x100, 0x4));
94
95 mt76_wr(dev, MT_RXQ_EXT_CTRL(MT_RXQ_MCU) + ofs, PREFETCH(0x140, 0x4));
96 mt76_wr(dev, MT_RXQ_EXT_CTRL(MT_RXQ_MCU_WA) + ofs, PREFETCH(0x180, 0x4));
> 97 if (!is_mt7915(&dev->mt76)) {
98 mt76_wr(dev, MT_RXQ_EXT_CTRL(MT_RXQ_MAIN_WA) + ofs, PREFETCH(0x1c0, 0x4));
99 base = 0x40;
100 }
101 mt76_wr(dev, MT_RXQ_EXT_CTRL(MT_RXQ_EXT_WA) + ofs, PREFETCH(0x1c0 + base, 0x4));
102 mt76_wr(dev, MT_RXQ_EXT_CTRL(MT_RXQ_MAIN) + ofs, PREFETCH(0x200 + base, 0x4));
103 mt76_wr(dev, MT_RXQ_EXT_CTRL(MT_RXQ_EXT) + ofs, PREFETCH(0x240 + base, 0x4));
104
105 /* for mt7915, the ring which is next the last
106 * used ring must be initialized.
107 */
108 if (is_mt7915(&dev->mt76)) {
109 ofs += 0x4;
110 mt76_wr(dev, MT_MCUQ_EXT_CTRL(MT_MCUQ_WA) + ofs, PREFETCH(0x140, 0x0));
111 mt76_wr(dev, MT_RXQ_EXT_CTRL(MT_RXQ_EXT_WA) + ofs, PREFETCH(0x200 + base, 0x0));
112 mt76_wr(dev, MT_RXQ_EXT_CTRL(MT_RXQ_EXT) + ofs, PREFETCH(0x280 + base, 0x0));
113 }
114 }
115
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0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx