Hi Peter,

[auto build test WARNING on char-misc/char-misc-testing]
[also build test WARNING on v4.10-rc8 next-20170216]
[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/Peter-Huewe/Fix-whole-native-SPI-TPM-driver/20170217-010419
config: x86_64-randconfig-x001-201707 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

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/char/tpm/tpm_tis_spi.c: In function 'tpm_tis_spi_transfer':
>> drivers/char/tpm/tpm_tis_spi.c:135:9: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized]
     return ret;
            ^~~

vim +/ret +135 drivers/char/tpm/tpm_tis_spi.c

dae9219c Peter Huewe       2017-02-16  119  			spi_xfer.tx_buf = buffer;
dae9219c Peter Huewe       2017-02-16  120  			spi_xfer.rx_buf = NULL;
dae9219c Peter Huewe       2017-02-16  121  		}
0edbfea5 Christophe Ricard 2016-05-19  122  
0edbfea5 Christophe Ricard 2016-05-19  123  		spi_message_init(&m);
0edbfea5 Christophe Ricard 2016-05-19  124  		spi_message_add_tail(&spi_xfer, &m);
0edbfea5 Christophe Ricard 2016-05-19  125  		ret = spi_sync_locked(phy->spi_device, &m);
4dea582e Peter Huewe       2017-02-16  126  		if (ret < 0)
4dea582e Peter Huewe       2017-02-16  127  			goto exit;
4dea582e Peter Huewe       2017-02-16  128  
4dea582e Peter Huewe       2017-02-16  129  		len -= transfer_len;
4dea582e Peter Huewe       2017-02-16  130  		buffer += transfer_len;
4dea582e Peter Huewe       2017-02-16  131  	}
0edbfea5 Christophe Ricard 2016-05-19  132  
0edbfea5 Christophe Ricard 2016-05-19  133  exit:
0edbfea5 Christophe Ricard 2016-05-19  134  	spi_bus_unlock(phy->spi_device->master);
0edbfea5 Christophe Ricard 2016-05-19 @135  	return ret;
0edbfea5 Christophe Ricard 2016-05-19  136  }
0edbfea5 Christophe Ricard 2016-05-19  137  
dae9219c Peter Huewe       2017-02-16  138  static int tpm_tis_spi_read_bytes(struct tpm_tis_data *data, u32 addr,
dae9219c Peter Huewe       2017-02-16  139  				  u16 len, u8 *result)
0edbfea5 Christophe Ricard 2016-05-19  140  {
dae9219c Peter Huewe       2017-02-16  141  	return tpm_tis_spi_transfer(data, addr, len, result, 0x80);
0edbfea5 Christophe Ricard 2016-05-19  142  }
0edbfea5 Christophe Ricard 2016-05-19  143  

:::::: The code at line 135 was first introduced by commit
:::::: 0edbfea537d10c0de5505d0413368aad71027663 tpm/tpm_tis_spi: Add support for spi phy

:::::: TO: Christophe Ricard <christophe.ricard@gmail.com>
:::::: CC: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

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