drivers/iio/dac/ltc2688.c:84:8: warning: Excessive padding in 'struct ltc2688_state' (35 padding bytes, where 3 is optimal). Optimal fields order: tx_data, rx_data, spi, regmap, iio_chan, vref, lock, regulators, channels, consider reordering the fields or...

From: kernel test robot
Date: Mon Jul 25 2022 - 12:05:48 EST

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tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: e0dccc3b76fb35bb257b4118367a883073d7390e
commit: 832cb9eeb9312dd2e14133681d3920b773ef1eac iio: dac: add support for ltc2688
date: 5 months ago
config: arm-randconfig-c002-20220718 (https://download.01.org/0day-ci/archive/20220726/202207260027.9tiGgEqR-lkp@xxxxxxxxx/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project d74b88c69dc2644bd0dc5d64e2d7413a0d4040e5)
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 arm cross compiling tool for clang build
# apt-get install binutils-arm-linux-gnueabi
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=832cb9eeb9312dd2e14133681d3920b773ef1eac
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 832cb9eeb9312dd2e14133681d3920b773ef1eac
# save the config file
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm clang-analyzer

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>

clang-analyzer warnings: (new ones prefixed by >>)
drivers/media/usb/em28xx/em28xx-core.c:636:6: note: Assuming field 'chip_id' is not equal to CHIP_ID_EM2874
if (dev->chip_id == CHIP_ID_EM2874 ||
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/media/usb/em28xx/em28xx-core.c:636:6: note: Left side of '||' is false
drivers/media/usb/em28xx/em28xx-core.c:637:6: note: Assuming field 'chip_id' is not equal to CHIP_ID_EM2884
dev->chip_id == CHIP_ID_EM2884 ||
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/media/usb/em28xx/em28xx-core.c:636:6: note: Left side of '||' is false
if (dev->chip_id == CHIP_ID_EM2874 ||
^
drivers/media/usb/em28xx/em28xx-core.c:638:6: note: Assuming field 'chip_id' is not equal to CHIP_ID_EM28174
dev->chip_id == CHIP_ID_EM28174 ||
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/media/usb/em28xx/em28xx-core.c:636:6: note: Left side of '||' is false
if (dev->chip_id == CHIP_ID_EM2874 ||
^
drivers/media/usb/em28xx/em28xx-core.c:639:6: note: Assuming field 'chip_id' is not equal to CHIP_ID_EM28178
dev->chip_id == CHIP_ID_EM28178) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/media/usb/em28xx/em28xx-core.c:636:2: note: Taking false branch
if (dev->chip_id == CHIP_ID_EM2874 ||
^
drivers/media/usb/em28xx/em28xx-core.c:668:9: note: 'start' is 1
start ? 0x10 : 0x00, 0x10);
^~~~~
drivers/media/usb/em28xx/em28xx-core.c:668:9: note: '?' condition is true
drivers/media/usb/em28xx/em28xx-core.c:667:8: note: Calling 'em28xx_write_reg_bits'
rc = em28xx_write_reg_bits(dev, EM28XX_R0C_USBSUSP,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/media/usb/em28xx/em28xx-core.c:211:11: note: Calling 'em28xx_read_reg'
oldval = em28xx_read_reg(dev, reg);
^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/media/usb/em28xx/em28xx-core.c:136:9: note: Calling 'em28xx_read_reg_req'
return em28xx_read_reg_req(dev, USB_REQ_GET_STATUS, reg);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/media/usb/em28xx/em28xx-core.c:125:2: note: 'val' declared without an initial value
u8 val;
^~~~~~
drivers/media/usb/em28xx/em28xx-core.c:127:8: note: Calling 'em28xx_read_reg_req_len'
ret = em28xx_read_reg_req_len(dev, req, reg, &val, 1);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/media/usb/em28xx/em28xx-core.c:83:6: note: Assuming field 'disconnected' is 0
if (dev->disconnected)
^~~~~~~~~~~~~~~~~
drivers/media/usb/em28xx/em28xx-core.c:83:2: note: Taking false branch
if (dev->disconnected)
^
drivers/media/usb/em28xx/em28xx-core.c:86:6: note: 'len' is <= URB_MAX_CTRL_SIZE
if (len > URB_MAX_CTRL_SIZE)
^~~
drivers/media/usb/em28xx/em28xx-core.c:86:2: note: Taking false branch
if (len > URB_MAX_CTRL_SIZE)
^
drivers/media/usb/em28xx/em28xx-core.c:93:6: note: Assuming 'ret' is < 0
if (ret < 0) {
^~~~~~~
drivers/media/usb/em28xx/em28xx-core.c:93:2: note: Taking true branch
if (ret < 0) {
^
drivers/media/usb/em28xx/em28xx-core.c:94:3: note: Assuming 'reg_debug' is 0
em28xx_regdbg("(pipe 0x%08x): IN: %02x %02x %02x %02x %02x %02x %02x %02x failed with error %i\n",
^
drivers/media/usb/em28xx/em28xx-core.c:60:6: note: expanded from macro 'em28xx_regdbg'
if (reg_debug) \
^~~~~~~~~
drivers/media/usb/em28xx/em28xx-core.c:94:3: note: Taking false branch
em28xx_regdbg("(pipe 0x%08x): IN: %02x %02x %02x %02x %02x %02x %02x %02x failed with error %i\n",
^
drivers/media/usb/em28xx/em28xx-core.c:60:2: note: expanded from macro 'em28xx_regdbg'
if (reg_debug) \
^
drivers/media/usb/em28xx/em28xx-core.c:94:3: note: Loop condition is false. Exiting loop
em28xx_regdbg("(pipe 0x%08x): IN: %02x %02x %02x %02x %02x %02x %02x %02x failed with error %i\n",
^
drivers/media/usb/em28xx/em28xx-core.c:59:36: note: expanded from macro 'em28xx_regdbg'
#define em28xx_regdbg(fmt, arg...) do { \
^
drivers/media/usb/em28xx/em28xx-core.c:127:8: note: Returning from 'em28xx_read_reg_req_len'
ret = em28xx_read_reg_req_len(dev, req, reg, &val, 1);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/media/usb/em28xx/em28xx-core.c:128:6: note: Assuming 'ret' is >= 0
if (ret < 0)
^~~~~~~
drivers/media/usb/em28xx/em28xx-core.c:128:2: note: Taking false branch
if (ret < 0)
^
drivers/media/usb/em28xx/em28xx-core.c:131:2: note: Undefined or garbage value returned to caller
return val;
^ ~~~
drivers/media/usb/em28xx/em28xx-core.c:674:5: warning: Value stored to 'rc' is never read [clang-analyzer-deadcode.DeadStores]
rc = em28xx_write_reg(dev, 0x13, 0x0c);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/media/usb/em28xx/em28xx-core.c:674:5: note: Value stored to 'rc' is never read
rc = em28xx_write_reg(dev, 0x13, 0x0c);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Suppressed 2 warnings (2 with check filters).
1 warning generated.
Suppressed 1 warnings (1 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
2 warnings generated.
>> drivers/iio/dac/ltc2688.c:84:8: warning: Excessive padding in 'struct ltc2688_state' (35 padding bytes, where 3 is optimal). Optimal fields order: tx_data, rx_data, spi, regmap, iio_chan, vref, lock, regulators, channels, consider reordering the fields or adding explicit padding members [clang-analyzer-optin.performance.Padding]
struct ltc2688_state {
~~~~~~~^~~~~~~~~~~~~~~
drivers/iio/dac/ltc2688.c:84:8: note: Excessive padding in 'struct ltc2688_state' (35 padding bytes, where 3 is optimal). Optimal fields order: tx_data, rx_data, spi, regmap, iio_chan, vref, lock, regulators, channels, consider reordering the fields or adding explicit padding members
struct ltc2688_state {
~~~~~~~^~~~~~~~~~~~~~~
drivers/iio/dac/ltc2688.c:253:11: warning: The left operand of '&' is a garbage value [clang-analyzer-core.UndefinedBinaryOperatorResult]
*code = FIELD_GET(LTC2688_DITHER_RAW_MASK, *code);
^
include/linux/bitfield.h:126:27: note: expanded from macro 'FIELD_GET'
(typeof(_mask))(((_reg) & (_mask)) >> __bf_shf(_mask)); \
^
drivers/iio/dac/ltc2688.c:498:2: note: 'val' declared without an initial value
u32 val;
^~~~~~~
drivers/iio/dac/ltc2688.c:500:6: note: Assuming 'private' is not equal to LTC2688_INPUT_B_AVAIL
if (private == LTC2688_INPUT_B_AVAIL)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/iio/dac/ltc2688.c:500:2: note: Taking false branch
if (private == LTC2688_INPUT_B_AVAIL)
^
drivers/iio/dac/ltc2688.c:505:6: note: Assuming 'private' is not equal to LTC2688_DITHER_OFF
if (private == LTC2688_DITHER_OFF)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/iio/dac/ltc2688.c:505:2: note: Taking false branch
if (private == LTC2688_DITHER_OFF)
^
drivers/iio/dac/ltc2688.c:508:8: note: Calling 'ltc2688_dac_code_read'
ret = ltc2688_dac_code_read(st, chan->channel, private, &val);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/iio/dac/ltc2688.c:245:6: note: Assuming 'ret' is not equal to 0
if (ret)
^~~
drivers/iio/dac/ltc2688.c:245:2: note: Taking true branch
if (ret)
^
drivers/iio/dac/ltc2688.c:246:3: note: Control jumps to line 250
goto out_unlock;
^
drivers/iio/dac/ltc2688.c:252:6: note: Assuming field 'toggle_chan' is false
if (!c->toggle_chan && input == LTC2688_INPUT_B)
^~~~~~~~~~~~~~~
drivers/iio/dac/ltc2688.c:252:6: note: Left side of '&&' is true
drivers/iio/dac/ltc2688.c:252:25: note: Assuming 'input' is equal to LTC2688_INPUT_B
if (!c->toggle_chan && input == LTC2688_INPUT_B)
^~~~~~~~~~~~~~~~~~~~~~~~
drivers/iio/dac/ltc2688.c:252:2: note: Taking true branch
if (!c->toggle_chan && input == LTC2688_INPUT_B)
^
drivers/iio/dac/ltc2688.c:253:11: note: Taking false branch
*code = FIELD_GET(LTC2688_DITHER_RAW_MASK, *code);
^
include/linux/bitfield.h:125:3: note: expanded from macro 'FIELD_GET'
__BF_FIELD_CHECK(_mask, _reg, 0U, "FIELD_GET: "); \
^
include/linux/bitfield.h:62:3: note: expanded from macro '__BF_FIELD_CHECK'
BUILD_BUG_ON_MSG(!__builtin_constant_p(_mask), \
^
include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG'
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
^
include/linux/compiler_types.h:346:2: note: expanded from macro 'compiletime_assert'
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^
include/linux/compiler_types.h:334:2: note: expanded from macro '_compiletime_assert'
__compiletime_assert(condition, msg, prefix, suffix)
^
include/linux/compiler_types.h:326:3: note: expanded from macro '__compiletime_assert'
if (!(condition)) \
^
drivers/iio/dac/ltc2688.c:253:11: note: Loop condition is false. Exiting loop
*code = FIELD_GET(LTC2688_DITHER_RAW_MASK, *code);
^
include/linux/bitfield.h:125:3: note: expanded from macro 'FIELD_GET'
__BF_FIELD_CHECK(_mask, _reg, 0U, "FIELD_GET: "); \
^
include/linux/bitfield.h:62:3: note: expanded from macro '__BF_FIELD_CHECK'
BUILD_BUG_ON_MSG(!__builtin_constant_p(_mask), \
^
include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG'
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
^
include/linux/compiler_types.h:346:2: note: expanded from macro 'compiletime_assert'
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^
include/linux/compiler_types.h:334:2: note: expanded from macro '_compiletime_assert'
__compiletime_assert(condition, msg, prefix, suffix)
^
include/linux/compiler_types.h:318:2: note: expanded from macro '__compiletime_assert'
do { \
^
drivers/iio/dac/ltc2688.c:253:11: note: Taking false branch
*code = FIELD_GET(LTC2688_DITHER_RAW_MASK, *code);
^
include/linux/bitfield.h:125:3: note: expanded from macro 'FIELD_GET'
__BF_FIELD_CHECK(_mask, _reg, 0U, "FIELD_GET: "); \
^
include/linux/bitfield.h:64:3: note: expanded from macro '__BF_FIELD_CHECK'
BUILD_BUG_ON_MSG((_mask) == 0, _pfx "mask is zero"); \
^
include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG'

vim +84 drivers/iio/dac/ltc2688.c

83
> 84 struct ltc2688_state {
85 struct spi_device *spi;
86 struct regmap *regmap;
87 struct regulator_bulk_data regulators[2];
88 struct ltc2688_chan channels[LTC2688_DAC_CHANNELS];
89 struct iio_chan_spec *iio_chan;
90 /* lock to protect against multiple access to the device and shared data */
91 struct mutex lock;
92 int vref;
93 /*
94 * DMA (thus cache coherency maintenance) requires the
95 * transfer buffers to live in their own cache lines.
96 */
97 u8 tx_data[6] ____cacheline_aligned;
98 u8 rx_data[3];
99 };
100

--
0-DAY CI Kernel Test Service
https://01.org/lkp

Next message: David Sterba: "Re: [PATCH] btrfs: Fix unused variable in load_free_space_cache()"
Previous message: Zhuo Chen: "[PATCH] PCI/ERR: Use pcie_aer_is_native() to judge whether OS owns AER"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]