From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Perches Date: Fri, 15 May 2015 17:10:26 +0000 Subject: Re: [patch] regulator: max77686: fix a shift wrapping bug Message-Id: <1431709826.15709.15.camel@perches.com> List-Id: References: <20150515092501.GB21508@mwanda> <5555C814.7030405@samsung.com> In-Reply-To: <5555C814.7030405@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Chanwoo Choi Cc: Dan Carpenter , Krzysztof Kozlowski , Liam Girdwood , Mark Brown , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org On Fri, 2015-05-15 at 19:19 +0900, Chanwoo Choi wrote: > On 05/15/2015 06:25 PM, Dan Carpenter wrote: > > We need to be able to handle more than 32 bits here because "id" can go > > up to MAX77686_BUCK9 (34). ->gpio_enabled is a u64 so that's fine > > already. > > > > Fixes: 3307e9025d29 ('regulator: max77686: Add GPIO control') > > Signed-off-by: Dan Carpenter Alternate suggested patch below: > > diff --git a/drivers/regulator/max77686.c b/drivers/regulator/max77686.c [] > > @@ -121,7 +121,7 @@ static unsigned int max77686_map_normal_mode(struct max77686_data *max77686, > > - if (max77686->gpio_enabled & (1 << id)) > > + if (max77686->gpio_enabled & (1ULL << id)) [] > > @@ -277,7 +277,7 @@ static int max77686_of_parse_cb(struct device_node *np, > > if (gpio_is_valid(config->ena_gpio)) { > > - max77686->gpio_enabled |= (1 << desc->id); > > + max77686->gpio_enabled |= (1ULL << desc->id); [] > Looks good to me. > Reviewed-by: Chanwoo Choi This could be better with DECLARE_BITMAP and test_bit/set_bit --- drivers/regulator/max77686.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/regulator/max77686.c b/drivers/regulator/max77686.c index 23b7c06..17ccf36 100644 --- a/drivers/regulator/max77686.c +++ b/drivers/regulator/max77686.c @@ -88,7 +88,7 @@ enum max77686_ramp_rate { }; struct max77686_data { - u64 gpio_enabled:MAX77686_REGULATORS; + DECLARE_BITMAP(gpio_enabled, MAX77686_REGULATORS); /* Array indexed by regulator id */ unsigned int opmode[MAX77686_REGULATORS]; @@ -121,7 +121,7 @@ static unsigned int max77686_map_normal_mode(struct max77686_data *max77686, case MAX77686_BUCK8: case MAX77686_BUCK9: case MAX77686_LDO20 ... MAX77686_LDO22: - if (max77686->gpio_enabled & (1 << id)) + if (test_bit(id, max77686->gpio_enabled)) return MAX77686_GPIO_CONTROL; } @@ -277,7 +277,7 @@ static int max77686_of_parse_cb(struct device_node *np, } if (gpio_is_valid(config->ena_gpio)) { - max77686->gpio_enabled |= (1 << desc->id); + set_bit(desc->id, max77686->gpio_enabled); return regmap_update_bits(config->regmap, desc->enable_reg, desc->enable_mask,