linux-kernel - Applied "regulator: core: Ensure we are at least in bounds for our constraints" to the regulator tree

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 23 Mar 2016 13:43:02 +0000
From:	Mark Brown <broonie@...nel.org>
To:	Ivaylo Dimitrov <ivo.g.dimitrov.75@...il.com>,
	Ivaylo Dimitrov <ivo.g.dimitrov.75@...il.com>,
	Mark Brown <broonie@...nel.org>
Cc:	linux-kernel@...r.kernel.org
Subject: Applied "regulator: core: Ensure we are at least in bounds for our constraints" to the regulator tree

The patch

   regulator: core: Ensure we are at least in bounds for our constraints

has been applied to the regulator tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From bae4fdc88d7f7dda1bfb3dd282978c617dbf16e3 Mon Sep 17 00:00:00 2001
From: Mark Brown <broonie@...nel.org>
Date: Mon, 21 Mar 2016 18:12:52 +0000
Subject: [PATCH] regulator: core: Ensure we are at least in bounds for our
 constraints

Currently we only attempt to set the voltage during constraints
application if an exact voltage is specified.  Extend this so that if
the currently set voltage for the regulator is outside the bounds set in
constraints we will move the voltage to the nearest constraint, raising
to the minimum or lowering to the maximum as needed.  This ensures that
drivers can probe without the hardware being driven out of spec.

Reported-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@...il.com>
Tested-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@...il.com>
Signed-off-by: Mark Brown <broonie@...nel.org>
---
 drivers/regulator/core.c | 32 +++++++++++++++++++++++++-------
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index e0b764284773..881c37e61f75 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -906,7 +906,8 @@ static int machine_constraints_voltage(struct regulator_dev *rdev,
 
 	/* do we need to apply the constraint voltage */
 	if (rdev->constraints->apply_uV &&
-	    rdev->constraints->min_uV == rdev->constraints->max_uV) {
+	    rdev->constraints->min_uV && rdev->constraints->max_uV) {
+		int target_min, target_max;
 		int current_uV = _regulator_get_voltage(rdev);
 		if (current_uV < 0) {
 			rdev_err(rdev,
@@ -914,15 +915,32 @@ static int machine_constraints_voltage(struct regulator_dev *rdev,
 				 current_uV);
 			return current_uV;
 		}
-		if (current_uV < rdev->constraints->min_uV ||
-		    current_uV > rdev->constraints->max_uV) {
+
+		/*
+		 * If we're below the minimum voltage move up to the
+		 * minimum voltage, if we're above the maximum voltage
+		 * then move down to the maximum.
+		 */
+		target_min = current_uV;
+		target_max = current_uV;
+
+		if (current_uV < rdev->constraints->min_uV) {
+			target_min = rdev->constraints->min_uV;
+			target_max = rdev->constraints->min_uV;
+		}
+
+		if (current_uV > rdev->constraints->max_uV) {
+			target_min = rdev->constraints->max_uV;
+			target_max = rdev->constraints->max_uV;
+		}
+
+		if (target_min != current_uV || target_max != current_uV) {
 			ret = _regulator_do_set_voltage(
-				rdev, rdev->constraints->min_uV,
-				rdev->constraints->max_uV);
+				rdev, target_min, target_max);
 			if (ret < 0) {
 				rdev_err(rdev,
-					"failed to apply %duV constraint(%d)\n",
-					rdev->constraints->min_uV, ret);
+					"failed to apply %d-%duV constraint(%d)\n",
+					target_min, target_max, ret);
 				return ret;
 			}
 		}
-- 
2.7.0