linux-kernel - [PATCH 2/5] regulator: core: Use parent voltage from the supply when bypassed

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:	Thu,  7 Apr 2016 16:22:36 +0200
From:	Thierry Reding <thierry.reding@...il.com>
To:	Mark Brown <broonie@...nel.org>
Cc:	Jon Hunter <jonathanh@...dia.com>,
	Liam Girdwood <lgirdwood@...il.com>,
	linux-kernel@...r.kernel.org
Subject: [PATCH 2/5] regulator: core: Use parent voltage from the supply when bypassed

From: Mark Brown <broonie@...nel.org>

When a regulator is in bypass mode it is functioning as a switch
returning the voltage set in the regulator will not give the voltage
being output by the regulator as it's just passing through its supply.
This means that when we are getting the voltage from a regulator we
should check to see if it is in bypass mode and if it is we should
report the voltage from the supply rather than that which is set on the
regulator.

Reported-by: Jon Hunter <jonathanh@...dia.com>
Signed-off-by: Mark Brown <broonie@...nel.org>
[treding@...dia.com: return early for bypass mode]
Signed-off-by: Thierry Reding <treding@...dia.com>
---
 drivers/regulator/core.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index cc0333a79924..23c8c4c86389 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -3118,6 +3118,20 @@ EXPORT_SYMBOL_GPL(regulator_sync_voltage);
 static int _regulator_get_voltage(struct regulator_dev *rdev)
 {
 	int sel, ret;
+	bool bypassed;
+
+	if (rdev->desc->ops->get_bypass) {
+		ret = rdev->desc->ops->get_bypass(rdev, &bypassed);
+		if (ret < 0)
+			return ret;
+		if (bypassed) {
+			/* if bypassed the regulator must have a supply */
+			if (!rdev->supply)
+				return -EINVAL;
+
+			return _regulator_get_voltage(rdev->supply->rdev);
+		}
+	}
 
 	if (rdev->desc->ops->get_voltage_sel) {
 		sel = rdev->desc->ops->get_voltage_sel(rdev);
-- 
2.8.0