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authorSuzuki K Poulose <suzuki.poulose@arm.com>2017-06-05 23:15:02 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-06-09 12:45:23 +0300
commitf73f20e1fcc9fcdc7557fd1c4b1b72f924478688 (patch)
tree05fdc622e212f99d3f25eafed313667511861005 /drivers/hwtracing
parenteb7bfcce69a9283db76e6d95ce9a9fcd7abc047a (diff)
downloadlinux-f73f20e1fcc9fcdc7557fd1c4b1b72f924478688.tar.xz
coresight: Disable the path only when the source is disabled
With a coresight tracing session, the components along the path from the source to sink are disabled after the source is disabled. However, if the source was not actually disabled due to active users, we should not disable the components in the path. Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing')
-rw-r--r--drivers/hwtracing/coresight/coresight.c19
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index 0c37356e417c..532a2acfa8cc 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -253,14 +253,22 @@ static int coresight_enable_source(struct coresight_device *csdev, u32 mode)
return 0;
}
-static void coresight_disable_source(struct coresight_device *csdev)
+/**
+ * coresight_disable_source - Drop the reference count by 1 and disable
+ * the device if there are no users left.
+ *
+ * @csdev - The coresight device to disable
+ *
+ * Returns true if the device has been disabled.
+ */
+static bool coresight_disable_source(struct coresight_device *csdev)
{
if (atomic_dec_return(csdev->refcnt) == 0) {
- if (source_ops(csdev)->disable) {
+ if (source_ops(csdev)->disable)
source_ops(csdev)->disable(csdev, NULL);
- csdev->enable = false;
- }
+ csdev->enable = false;
}
+ return !csdev->enable;
}
void coresight_disable_path(struct list_head *path)
@@ -629,7 +637,7 @@ void coresight_disable(struct coresight_device *csdev)
if (ret)
goto out;
- if (!csdev->enable)
+ if (!csdev->enable || !coresight_disable_source(csdev))
goto out;
switch (csdev->subtype.source_subtype) {
@@ -647,7 +655,6 @@ void coresight_disable(struct coresight_device *csdev)
break;
}
- coresight_disable_source(csdev);
coresight_disable_path(path);
coresight_release_path(path);