diff options
| author | Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> | 2024-07-09 14:59:31 +0200 |
|---|---|---|
| committer | Daniel Lezcano <daniel.lezcano@linaro.org> | 2024-07-15 13:31:40 +0200 |
| commit | e90c369cc2ffcf7145a46448de101f715a1f5584 (patch) | |
| tree | bca0c199eca6982a8b74aafdd00fc7967cb3d2eb /drivers/thermal | |
| parent | 6f48290b1a18dba5870920188725eee6fe603ee6 (diff) | |
| download | lwn-e90c369cc2ffcf7145a46448de101f715a1f5584.tar.gz lwn-e90c369cc2ffcf7145a46448de101f715a1f5584.zip | |
thermal/drivers/broadcom: Fix race between removal and clock disable
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@vger.kernel.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240709-thermal-probe-v1-1-241644e2b6e0@linaro.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Diffstat (limited to 'drivers/thermal')
| -rw-r--r-- | drivers/thermal/broadcom/bcm2835_thermal.c | 19 |
1 files changed, 4 insertions, 15 deletions
diff --git a/drivers/thermal/broadcom/bcm2835_thermal.c b/drivers/thermal/broadcom/bcm2835_thermal.c index 5c1cebe07580..3b1030fc4fbf 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 = { |