Re: [PATCH v4 2/2] iio: adc: ti-ads7950: add GPIO support

[Dan Carpenter]

Hi Justin,

url:    https://github.com/0day-ci/linux/commits/justinpopo6-gmail-com/iio-adc-ads7950-add-gpio-support/20190301-201828
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg

smatch warnings:
drivers/iio/adc/ti-ads7950.c:530 ti_ads7950_init_hw() error: double unlock 'mutex:&st->slock'

# https://github.com/0day-ci/linux/commit/5290a7752b734ae0b2f5b343bd761366decdbbeb
git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout 5290a7752b734ae0b2f5b343bd761366decdbbeb
vim +530 drivers/iio/adc/ti-ads7950.c

5290a775 Justin Chen 2019-02-28  506  
5290a775 Justin Chen 2019-02-28  507  static int ti_ads7950_init_hw(struct ti_ads7950_state *st)
5290a775 Justin Chen 2019-02-28  508  {
5290a775 Justin Chen 2019-02-28  509  	int ret = 0;
5290a775 Justin Chen 2019-02-28  510  
5290a775 Justin Chen 2019-02-28  511  	mutex_lock(&st->slock);
5290a775 Justin Chen 2019-02-28  512  
5290a775 Justin Chen 2019-02-28  513  	/* Settings for Manual/Auto1/Auto2 commands */
5290a775 Justin Chen 2019-02-28  514  	/* Default to 5v ref */
5290a775 Justin Chen 2019-02-28  515  	st->cmd_settings_bitmask = TI_ADS7950_CR_RANGE_5V;
5290a775 Justin Chen 2019-02-28  516  	st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st);
5290a775 Justin Chen 2019-02-28  517  	ret = spi_sync(st->spi, &st->scan_single_msg);
5290a775 Justin Chen 2019-02-28  518  	if (ret)
5290a775 Justin Chen 2019-02-28  519  		goto out;
5290a775 Justin Chen 2019-02-28  520  
5290a775 Justin Chen 2019-02-28  521  	/* Settings for GPIO command */
5290a775 Justin Chen 2019-02-28  522  	st->gpio_cmd_settings_bitmask = 0x0;
5290a775 Justin Chen 2019-02-28  523  	st->single_tx = TI_ADS7950_GPIO_CMD_SETTINGS(st);
5290a775 Justin Chen 2019-02-28  524  	ret = spi_sync(st->spi, &st->scan_single_msg);
5290a775 Justin Chen 2019-02-28  525  	mutex_unlock(&st->slock);
                                        ^^^^^^^^^^^^^^^^^^^^^^^^

5290a775 Justin Chen 2019-02-28  526  	if (ret)
5290a775 Justin Chen 2019-02-28  527  		goto out;
5290a775 Justin Chen 2019-02-28  528  
5290a775 Justin Chen 2019-02-28  529  out:
5290a775 Justin Chen 2019-02-28 @530  	mutex_unlock(&st->slock);
                                        ^^^^^^^^^^^^^^^^^^^^^^^^

It's a bit disappointing that mutex_unlock() doesn't generate a warning
at runtime...  :(

5290a775 Justin Chen 2019-02-28  531  
5290a775 Justin Chen 2019-02-28  532  	return ret;
5290a775 Justin Chen 2019-02-28  533  }
5290a775 Justin Chen 2019-02-28  534  

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