Messages in this thread | | | Subject | Re: [PATCH] coresight: add PM runtime calls to coresight_simple_func() | From | Sudeep Holla <> | Date | Thu, 23 Jun 2016 17:37:12 +0100 |
| |
On 17/06/16 18:41, Mathieu Poirier wrote: > 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.poirier@linaro.org> > --- > drivers/hwtracing/coresight/coresight-priv.h | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h > index ad975c58080d..b047241e7496 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 +43,10 @@ static ssize_t name##_show(struct device *_dev, \ > struct device_attribute *attr, char *buf) \ > { \ > type *drvdata = dev_get_drvdata(_dev->parent); \ > + pm_runtime_get_sync(_dev->parent); \ > return scnprintf(buf, PAGE_SIZE, "0x%x\n", \ > readl_relaxed(drvdata->base + offset)); \ > + pm_runtime_put_sync(_dev->parent); \
This is wrong, I just noticed when I was playing around this. Perhaps you meant to do this before returning ? I wonder why compiler doesn't throw any error.
-- Regards, Sudeep
| |