intel_th: Fix activating a subdevice without a driver

[cascardo/linux.git] / drivers / hwtracing / intel_th / core.c

diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c
index db06919..2033947 100644 (file)
--- a/drivers/hwtracing/intel_th/core.c
+++ b/drivers/hwtracing/intel_th/core.c
@@ -183,7 +183,11 @@ static DEVICE_ATTR_RO(port);
 
 static int intel_th_output_activate(struct intel_th_device *thdev)
 {
-       struct intel_th_driver *thdrv = to_intel_th_driver(thdev->dev.driver);
+       struct intel_th_driver *thdrv =
+               to_intel_th_driver_or_null(thdev->dev.driver);
+
+       if (!thdrv)
+               return -ENODEV;
 
        if (thdrv->activate)
                return thdrv->activate(thdev);
@@ -195,7 +199,11 @@ static int intel_th_output_activate(struct intel_th_device *thdev)
 
 static void intel_th_output_deactivate(struct intel_th_device *thdev)
 {
-       struct intel_th_driver *thdrv = to_intel_th_driver(thdev->dev.driver);
+       struct intel_th_driver *thdrv =
+               to_intel_th_driver_or_null(thdev->dev.driver);
+
+       if (!thdrv)
+               return;
 
        if (thdrv->deactivate)
                thdrv->deactivate(thdev);