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path: root/drivers/hwtracing/intel_th/core.c
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Diffstat (limited to 'drivers/hwtracing/intel_th/core.c')
-rw-r--r--drivers/hwtracing/intel_th/core.c21
1 files changed, 18 insertions, 3 deletions
diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c
index ca232ec565e8..c9ac3dc65113 100644
--- a/drivers/hwtracing/intel_th/core.c
+++ b/drivers/hwtracing/intel_th/core.c
@@ -1021,15 +1021,30 @@ int intel_th_set_output(struct intel_th_device *thdev,
{
struct intel_th_device *hub = to_intel_th_hub(thdev);
struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
+ int ret;
/* In host mode, this is up to the external debugger, do nothing. */
if (hub->host_mode)
return 0;
- if (!hubdrv->set_output)
- return -ENOTSUPP;
+ /*
+ * hub is instantiated together with the source device that
+ * calls here, so guaranteed to be present.
+ */
+ hubdrv = to_intel_th_driver(hub->dev.driver);
+ if (!hubdrv || !try_module_get(hubdrv->driver.owner))
+ return -EINVAL;
+
+ if (!hubdrv->set_output) {
+ ret = -ENOTSUPP;
+ goto out;
+ }
+
+ ret = hubdrv->set_output(hub, master);
- return hubdrv->set_output(hub, master);
+out:
+ module_put(hubdrv->driver.owner);
+ return ret;
}
EXPORT_SYMBOL_GPL(intel_th_set_output);