Hi Jinlong Mao

Please can you resend this as a normal patch to upstream maintainers / reviewers, this and the arm-kernel mailing lists (plus any other interested parties).

Describe the problem you see without the fix - does this cause a crash / bug or just not work?

Add a fixes tag along with your signed-off tag

On Sun, 18 Dec 2022 at 09:24, Jinlong Mao quic_jinlmao@quicinc.com wrote:

Hi James & Mike,

Here is the change I want to make for this issue. Please help to review. If it is ok for you, I will push the patch to linux mainline.

diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c index 6d59c815ecf5..513f133de415 100644 --- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c @@ -108,10 +108,18 @@ static ssize_t enable_store(struct device *dev, if (ret) return ret;

•   if (val)
  

•   if (val) {
  

•           ret = pm_runtime_get_sync(dev->parent);
  

•           if (ret) {
  

•                   pm_runtime_put_noidle(dev->parent);
  

•                   return ret;
  

•           }
  

use pm_runtime_resume_and_get() to avoid needing the pm_runtime_put_noidle on error.

             ret = cti_enable(drvdata->csdev);

if enable fails you need to pm_runtime_put....

Thanks and regards

Mike

•   else
  

•   } else {
             ret = cti_disable(drvdata->csdev);
  

•           pm_runtime_put(dev->parent);
  

•   }
  

•    if (ret)
             return ret;
     return size;
  
  

Thanks Jinlong Mao

On 12/17/2022 10:58 PM, Jinlong Mao wrote:

...

Hi James & Mike,

With this patch "[PATCH] coresight: cti: Fix hang in cti_disable_hw()", runtime PM calls are removed in cti_enable_hw/cti_disable_hw. There will be register access issue when write 1 to enable sysfs node of CTI directly as clock is not enabled for accessing CTI registers.

echo 1 > cti0/enable static ssize_t enable_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size)

Is there fix for the enable_store case ?

Thanks Jinlong Mao