This is a note to let you know that I've just added the patch titled
thermal/drivers/broadcom: Fix race between removal and clock disable
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
thermal-drivers-broadcom-fix-race-between-removal-an.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2baa80182561a0e62050aa262b1e09abb84af0d7
Author: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Date: Tue Jul 9 14:59:31 2024 +0200
thermal/drivers/broadcom: Fix race between removal and clock disable
[ Upstream commit e90c369cc2ffcf7145a46448de101f715a1f5584 ]
During the probe, driver enables clocks necessary to access registers
(in get_temp()) and then registers thermal zone with managed-resources
(devm) interface. Removal of device is not done in reversed order,
because:
1. Clock will be disabled in driver remove() callback - thermal zone is
still registered and accessible to users,
2. devm interface will unregister thermal zone.
This leaves short window between (1) and (2) for accessing the
get_temp() callback with disabled clock.
Fix this by enabling clock also via devm-interface, so entire cleanup
path will be in proper, reversed order.
Fixes: 8454c8c09c77 ("thermal/drivers/bcm2835: Remove buggy call to thermal_of_zone_unregister")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240709-thermal-probe-v1-1-241644e2b6e0@xxxxxxxxxx
Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/thermal/broadcom/bcm2835_thermal.c b/drivers/thermal/broadcom/bcm2835_thermal.c
index 5c1cebe075801..3b1030fc4fbfe 100644
--- a/drivers/thermal/broadcom/bcm2835_thermal.c
+++ b/drivers/thermal/broadcom/bcm2835_thermal.c
@@ -185,7 +185,7 @@ static int bcm2835_thermal_probe(struct platform_device *pdev)
return err;
}
- data->clk = devm_clk_get(&pdev->dev, NULL);
+ data->clk = devm_clk_get_enabled(&pdev->dev, NULL);
if (IS_ERR(data->clk)) {
err = PTR_ERR(data->clk);
if (err != -EPROBE_DEFER)
@@ -193,10 +193,6 @@ static int bcm2835_thermal_probe(struct platform_device *pdev)
return err;
}
- err = clk_prepare_enable(data->clk);
- if (err)
- return err;
-
rate = clk_get_rate(data->clk);
if ((rate < 1920000) || (rate > 5000000))
dev_warn(&pdev->dev,
@@ -211,7 +207,7 @@ static int bcm2835_thermal_probe(struct platform_device *pdev)
dev_err(&pdev->dev,
"Failed to register the thermal device: %d\n",
err);
- goto err_clk;
+ return err;
}
/*
@@ -236,7 +232,7 @@ static int bcm2835_thermal_probe(struct platform_device *pdev)
dev_err(&pdev->dev,
"Not able to read trip_temp: %d\n",
err);
- goto err_tz;
+ return err;
}
/* set bandgap reference voltage and enable voltage regulator */
@@ -269,17 +265,11 @@ static int bcm2835_thermal_probe(struct platform_device *pdev)
*/
err = thermal_add_hwmon_sysfs(tz);
if (err)
- goto err_tz;
+ return err;
bcm2835_thermal_debugfs(pdev);
return 0;
-err_tz:
- devm_thermal_of_zone_unregister(&pdev->dev, tz);
-err_clk:
- clk_disable_unprepare(data->clk);
-
- return err;
}
static void bcm2835_thermal_remove(struct platform_device *pdev)
@@ -287,7 +277,6 @@ static void bcm2835_thermal_remove(struct platform_device *pdev)
struct bcm2835_thermal_data *data = platform_get_drvdata(pdev);
debugfs_remove_recursive(data->debugfsdir);
- clk_disable_unprepare(data->clk);
}
static struct platform_driver bcm2835_thermal_driver = {
