It is mandatory to enable a coresight block's power domain before
trying to access management registers. Otherwise the transaction
simply stalls, leading to a system hang.
Signed-off-by: Mathieu Poirier <mathieu.poir...@linaro.org>
---
Change from V1:
- Fix erroneous return point in the macro.
drivers/hwtracing/coresight/coresight-priv.h | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-priv.h
b/drivers/hwtracing/coresight/coresight-priv.h
index ad975c58080d..decfd52b5dc3 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -16,6 +16,7 @@
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/coresight.h>
+#include <linux/pm_runtime.h>
/*
* Coresight management registers (0xf00-0xfcc)
@@ -42,8 +43,11 @@ static ssize_t name##_show(struct device *_dev,
\
struct device_attribute *attr, char *buf) \
{ \
type *drvdata = dev_get_drvdata(_dev->parent); \
- return scnprintf(buf, PAGE_SIZE, "0x%x\n", \
- readl_relaxed(drvdata->base + offset)); \
+ u32 val; \
+ pm_runtime_get_sync(_dev->parent); \
+ val = readl_relaxed(drvdata->base + offset); \
+ pm_runtime_put_sync(_dev->parent); \
+ return scnprintf(buf, PAGE_SIZE, "0x%x\n", val); \
} \
static DEVICE_ATTR_RO(name)
--
2.7.4
