drivers/spi/spi-cadence-quadspi.c:250:18: warning: Shifting signed 32-bit value by 31 bits is undefined behaviour

drivers/spi/spi-cadence-quadspi.c:250:18: warning: Shifting signed 32-bit value by 31 bits is undefined behaviour

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 2334 bytes --]

CC: kbuild-all(a)lists.01.org
CC: linux-kernel(a)vger.kernel.org
TO: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
CC: Mark Brown <broonie@kernel.org>
CC: Vignesh Raghavendra <vigneshr@ti.com>
CC: Tudor Ambarus <tudor.ambarus@microchip.com>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   7a7fd0de4a9804299793e564a555a49c1fc924cb
commit: 31fb632b5d43ca16713095b3a4fe17e3d7331e28 spi: Move cadence-quadspi driver to drivers/spi/
date:   9 months ago
:::::: branch date: 16 hours ago
:::::: commit date: 9 months ago
compiler: nds32le-linux-gcc (GCC) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


cppcheck possible warnings: (new ones prefixed by >>, may not real problems)

>> drivers/spi/spi-cadence-quadspi.c:250:18: warning: Shifting signed 32-bit value by 31 bits is undefined behaviour [shiftTooManyBitsSigned]
    return reg & (1 << CQSPI_REG_CONFIG_IDLE_LSB);
                    ^

vim +250 drivers/spi/spi-cadence-quadspi.c

14062341053690 drivers/mtd/spi-nor/cadence-quadspi.c Graham Moore 2016-06-04  245  
14062341053690 drivers/mtd/spi-nor/cadence-quadspi.c Graham Moore 2016-06-04  246  static bool cqspi_is_idle(struct cqspi_st *cqspi)
14062341053690 drivers/mtd/spi-nor/cadence-quadspi.c Graham Moore 2016-06-04  247  {
14062341053690 drivers/mtd/spi-nor/cadence-quadspi.c Graham Moore 2016-06-04  248  	u32 reg = readl(cqspi->iobase + CQSPI_REG_CONFIG);
14062341053690 drivers/mtd/spi-nor/cadence-quadspi.c Graham Moore 2016-06-04  249  
14062341053690 drivers/mtd/spi-nor/cadence-quadspi.c Graham Moore 2016-06-04 @250  	return reg & (1 << CQSPI_REG_CONFIG_IDLE_LSB);
14062341053690 drivers/mtd/spi-nor/cadence-quadspi.c Graham Moore 2016-06-04  251  }
14062341053690 drivers/mtd/spi-nor/cadence-quadspi.c Graham Moore 2016-06-04  252  

:::::: The code@line 250 was first introduced by commit
:::::: 140623410536905fa6ab737b625decfde6c64a72 mtd: spi-nor: Add driver for Cadence Quad SPI Flash Controller

:::::: TO: Graham Moore <grmoore@opensource.altera.com>
:::::: CC: Brian Norris <computersforpeace@gmail.com>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

drivers/spi/spi-cadence-quadspi.c:250:18: warning: Shifting signed 32-bit value by 31 bits is undefined behaviour

[Dan Carpenter]

[-- Attachment #1: Type: text/plain, Size: 1912 bytes --]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git  master
head:   7a7fd0de4a9804299793e564a555a49c1fc924cb
commit: 31fb632b5d43ca16713095b3a4fe17e3d7331e28 spi: Move cadence-quadspi driver to drivers/spi/
compiler: nds32le-linux-gcc (GCC) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

cppcheck possible warnings: (new ones prefixed by >>, may not real problems)

>> drivers/spi/spi-cadence-quadspi.c:250:18: warning: Shifting signed 32-bit value by 31 bits is undefined behaviour [shiftTooManyBitsSigned]
    return reg & (1 << CQSPI_REG_CONFIG_IDLE_LSB);

vim +250 drivers/spi/spi-cadence-quadspi.c

14062341053690 drivers/mtd/spi-nor/cadence-quadspi.c Graham Moore 2016-06-04  246  static bool cqspi_is_idle(struct cqspi_st *cqspi)
14062341053690 drivers/mtd/spi-nor/cadence-quadspi.c Graham Moore 2016-06-04  247  {
14062341053690 drivers/mtd/spi-nor/cadence-quadspi.c Graham Moore 2016-06-04  248  	u32 reg = readl(cqspi->iobase + CQSPI_REG_CONFIG);
14062341053690 drivers/mtd/spi-nor/cadence-quadspi.c Graham Moore 2016-06-04  249  
14062341053690 drivers/mtd/spi-nor/cadence-quadspi.c Graham Moore 2016-06-04 @250  	return reg & (1 << CQSPI_REG_CONFIG_IDLE_LSB);
                                                                                                           ^^^^^^^^^^^^^^^^^^^^^^^^^
CQSPI_REG_CONFIG_IDLE_LSB is 31 and reg is a u32 so this is very
puzzling.

14062341053690 drivers/mtd/spi-nor/cadence-quadspi.c Graham Moore 2016-06-04  251  }

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org 
_______________________________________________
kbuild mailing list -- kbuild(a)lists.01.org
To unsubscribe send an email to kbuild-leave@lists.01.org