linux-kernel - [PATCH V2] thermal: imx: correct suspend/resume flow

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-next>] [day] [month] [year] [list]

Date:	Tue, 24 Dec 2013 09:43:24 -0500
From:	Anson Huang <b20788@...escale.com>
To:	<rui.zhang@...el.com>, <shawn.guo@...aro.org>,
	<eduardo.valentin@...com>
CC:	<linux-pm@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: [PATCH V2] thermal: imx: correct suspend/resume flow

Fixes regression introduced by:

commit 37713a1e8e4c1a1067ad4c99296f78d3c82ed9c4
Author: Philipp Zabel <p.zabel@...gutronix.de>
Date:   Thu Aug 1 18:33:12 2013 +0200

    thermal: imx: implement thermal alarm interrupt handling

The commit 37713a1e8e4 makes imx thermal sensor always powered up as alarm
function is enabled, but the suspend callback of imx thermal returns
success only if thermal sensor is powered down, so it will always returns
fail hence break system's suspend, this patch disables imx thermal sensor
before suspend and re-enable it after resume.

Signed-off-by: Anson Huang <b20788@...escale.com>
---
 drivers/thermal/imx_thermal.c |   31 +++++++++++++++++--------------
 1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
index cbb16f3..9a9a6c2 100644
--- a/drivers/thermal/imx_thermal.c
+++ b/drivers/thermal/imx_thermal.c
@@ -510,27 +510,30 @@ static int imx_thermal_suspend(struct device *dev)
 {
 	struct imx_thermal_data *data = dev_get_drvdata(dev);
 	struct regmap *map = data->tempmon;
-	u32 val;
 
-	regmap_read(map, TEMPSENSE0, &val);
-	if ((val & TEMPSENSE0_POWER_DOWN) == 0) {
-		/*
-		 * If a measurement is taking place, wait for a long enough
-		 * time for it to finish, and then check again.  If it still
-		 * does not finish, something must go wrong.
-		 */
-		udelay(50);
-		regmap_read(map, TEMPSENSE0, &val);
-		if ((val & TEMPSENSE0_POWER_DOWN) == 0)
-			return -ETIMEDOUT;
-	}
+	/*
+	 * Need to disable thermal sensor, otherwise, when thermal core
+	 * try to get temperature before thermal sensor resume, a wrong
+	 * temperature will be read as the thermal sensor is powered
+	 * down.
+	 */
+	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
+	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
+	data->mode = THERMAL_DEVICE_DISABLED;
 
 	return 0;
 }
 
 static int imx_thermal_resume(struct device *dev)
 {
-	/* Nothing to do for now */
+	struct imx_thermal_data *data = dev_get_drvdata(dev);
+	struct regmap *map = data->tempmon;
+
+	/* Enabled thermal sensor after resume */
+	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
+	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
+	data->mode = THERMAL_DEVICE_ENABLED;
+
 	return 0;
 }
 #endif
-- 
1.7.9.5


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/