diff mbox

regulator: s2mps11: Fix GPIO suspend enable shift wrapping bug

Message ID 1432696928-4690-1-git-send-email-k.kozlowski@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Krzysztof Kozlowski May 27, 2015, 3:22 a.m. UTC
Status of enabling suspend mode for regulator was stored in bitmap-like
long integer.

However since adding support for S2MPU02 the number of regulators
exceeded 32 so on devices with more than 32 regulators (S2MPU02 and
S2MPS13) overflow happens when shifting the bit. This could lead to
enabling suspend mode for completely different regulator than intended
or to switching different regulator to other mode (e.g. from always
enabled to controlled by PWRHOLD pin). Both cases could result in larger
energy usage and issues when suspending to RAM.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: <stable@vger.kernel.org>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 00e2573d2c10 ("regulator: s2mps11: Add support S2MPU02 regulator device")
---
 drivers/regulator/s2mps11.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

Comments

Mark Brown May 28, 2015, 2:44 p.m. UTC | #1
On Wed, May 27, 2015 at 12:22:08PM +0900, Krzysztof Kozlowski wrote:
> Status of enabling suspend mode for regulator was stored in bitmap-like
> long integer.

Applied, thanks.
Krzysztof Kozlowski June 24, 2015, 4:02 a.m. UTC | #2
2015-05-28 23:44 GMT+09:00 Mark Brown <broonie@kernel.org>:
> On Wed, May 27, 2015 at 12:22:08PM +0900, Krzysztof Kozlowski wrote:
>> Status of enabling suspend mode for regulator was stored in bitmap-like
>> long integer.
>
> Applied, thanks.

Mark, what happened with this patch? I can't find it in your tree.
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Mark Brown June 24, 2015, 9:31 a.m. UTC | #3
On Wed, Jun 24, 2015 at 01:02:28PM +0900, Krzysztof Kozlowski wrote:
> 2015-05-28 23:44 GMT+09:00 Mark Brown <broonie@kernel.org>:
> > On Wed, May 27, 2015 at 12:22:08PM +0900, Krzysztof Kozlowski wrote:
> >> Status of enabling suspend mode for regulator was stored in bitmap-like
> >> long integer.

> > Applied, thanks.

> Mark, what happened with this patch? I can't find it in your tree.

I don't know.  If it's not there it's not there and you'll need to
resend, sorry.  There were some problems with error handling for bad
networks when pushing things but it looks like this was after I fixed
those.
Krzysztof Kozlowski June 24, 2015, 10:43 a.m. UTC | #4
2015-06-24 18:31 GMT+09:00 Mark Brown <broonie@kernel.org>:
> On Wed, Jun 24, 2015 at 01:02:28PM +0900, Krzysztof Kozlowski wrote:
>> 2015-05-28 23:44 GMT+09:00 Mark Brown <broonie@kernel.org>:
>> > On Wed, May 27, 2015 at 12:22:08PM +0900, Krzysztof Kozlowski wrote:
>> >> Status of enabling suspend mode for regulator was stored in bitmap-like
>> >> long integer.
>
>> > Applied, thanks.
>
>> Mark, what happened with this patch? I can't find it in your tree.
>
> I don't know.  If it's not there it's not there and you'll need to
> resend, sorry.  There were some problems with error handling for bad
> networks when pushing things but it looks like this was after I fixed
> those.

Okay, it happens. If you don't mind, I'll resend now, during merge
window. If it is bad timing, then let me know or postpone the patch.
This is a fix so in my humble opinion it's a candidate for 4.2-rc
(although it would be nice if this could sit in linux-next for a
while).

Best regards,
Krzysztof
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diff mbox

Patch

diff --git a/drivers/regulator/s2mps11.c b/drivers/regulator/s2mps11.c
index 326ffb553371..72fc3c32db49 100644
--- a/drivers/regulator/s2mps11.c
+++ b/drivers/regulator/s2mps11.c
@@ -34,6 +34,8 @@ 
 #include <linux/mfd/samsung/s2mps14.h>
 #include <linux/mfd/samsung/s2mpu02.h>
 
+/* The highest number of possible regulators for supported devices. */
+#define S2MPS_REGULATOR_MAX		S2MPS13_REGULATOR_MAX
 struct s2mps11_info {
 	unsigned int rdev_num;
 	int ramp_delay2;
@@ -49,7 +51,7 @@  struct s2mps11_info {
 	 * One bit for each S2MPS13/S2MPS14/S2MPU02 regulator whether
 	 * the suspend mode was enabled.
 	 */
-	unsigned long long s2mps14_suspend_state:50;
+	DECLARE_BITMAP(suspend_state, S2MPS_REGULATOR_MAX);
 
 	/* Array of size rdev_num with GPIO-s for external sleep control */
 	int *ext_control_gpio;
@@ -500,7 +502,7 @@  static int s2mps14_regulator_enable(struct regulator_dev *rdev)
 	switch (s2mps11->dev_type) {
 	case S2MPS13X:
 	case S2MPS14X:
-		if (s2mps11->s2mps14_suspend_state & (1 << rdev_get_id(rdev)))
+		if (test_bit(rdev_get_id(rdev), s2mps11->suspend_state))
 			val = S2MPS14_ENABLE_SUSPEND;
 		else if (gpio_is_valid(s2mps11->ext_control_gpio[rdev_get_id(rdev)]))
 			val = S2MPS14_ENABLE_EXT_CONTROL;
@@ -508,7 +510,7 @@  static int s2mps14_regulator_enable(struct regulator_dev *rdev)
 			val = rdev->desc->enable_mask;
 		break;
 	case S2MPU02:
-		if (s2mps11->s2mps14_suspend_state & (1 << rdev_get_id(rdev)))
+		if (test_bit(rdev_get_id(rdev), s2mps11->suspend_state))
 			val = S2MPU02_ENABLE_SUSPEND;
 		else
 			val = rdev->desc->enable_mask;
@@ -562,7 +564,7 @@  static int s2mps14_regulator_set_suspend_disable(struct regulator_dev *rdev)
 	if (ret < 0)
 		return ret;
 
-	s2mps11->s2mps14_suspend_state |= (1 << rdev_get_id(rdev));
+	set_bit(rdev_get_id(rdev), s2mps11->suspend_state);
 	/*
 	 * Don't enable suspend mode if regulator is already disabled because
 	 * this would effectively for a short time turn on the regulator after
@@ -960,18 +962,22 @@  static int s2mps11_pmic_probe(struct platform_device *pdev)
 	case S2MPS11X:
 		s2mps11->rdev_num = ARRAY_SIZE(s2mps11_regulators);
 		regulators = s2mps11_regulators;
+		BUILD_BUG_ON(S2MPS_REGULATOR_MAX < s2mps11->rdev_num);
 		break;
 	case S2MPS13X:
 		s2mps11->rdev_num = ARRAY_SIZE(s2mps13_regulators);
 		regulators = s2mps13_regulators;
+		BUILD_BUG_ON(S2MPS_REGULATOR_MAX < s2mps11->rdev_num);
 		break;
 	case S2MPS14X:
 		s2mps11->rdev_num = ARRAY_SIZE(s2mps14_regulators);
 		regulators = s2mps14_regulators;
+		BUILD_BUG_ON(S2MPS_REGULATOR_MAX < s2mps11->rdev_num);
 		break;
 	case S2MPU02:
 		s2mps11->rdev_num = ARRAY_SIZE(s2mpu02_regulators);
 		regulators = s2mpu02_regulators;
+		BUILD_BUG_ON(S2MPS_REGULATOR_MAX < s2mps11->rdev_num);
 		break;
 	default:
 		dev_err(&pdev->dev, "Invalid device type: %u\n",