[PATCH v10 18/24] coresight: cti: Fix bug clearing sysfs links on callback

From: Tingwei Zhang <tingwei@codeaurora.org>
To: Mathieu Poirier <mathieu.poirier@linaro.org>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Mike Leach <mike.leach@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Leo Yan <leo.yan@linaro.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	Russell King <linux@armlinux.org.uk>,
	Kim Phillips <kim.phillips@arm.com>,
	Mian Yousaf Kaukab <ykaukab@suse.de>,
	tsoni@codeaurora.org,
	Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>,
	Mao Jinlong <jinlmao@codeaurora.org>,
	coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Tingwei Zhang <tingwei@codeaurora.org>
Subject: [PATCH v10 18/24] coresight: cti: Fix bug clearing sysfs links on callback
Date: Fri, 21 Aug 2020 11:44:39 +0800	[thread overview]
Message-ID: <20200821034445.967-19-tingwei@codeaurora.org> (raw)
In-Reply-To: <20200821034445.967-1-tingwei@codeaurora.org>

From: Mike Leach <mike.leach@linaro.org>

During module unload, a coresight driver module will call back into
the CTI driver to remove any links between the two devices.

The current code has 2 issues:-
1) in the CTI driver the matching code is matching to the wrong device
so misses all the links.
2) The callback is called too late in the unload process resulting in a
crash.

This fixes both the issues.

Fixes: 177af8285b59 ("coresight: cti: Enable CTI associated with devices")
Reported-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 drivers/hwtracing/coresight/coresight-cti.c | 2 +-
 drivers/hwtracing/coresight/coresight.c     | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-cti.c b/drivers/hwtracing/coresight/coresight-cti.c
index 73304374a155..ec286d617b73 100644
--- a/drivers/hwtracing/coresight/coresight-cti.c
+++ b/drivers/hwtracing/coresight/coresight-cti.c
@@ -608,7 +608,7 @@ static void cti_remove_assoc_from_csdev(struct coresight_device *csdev)
 		ctidrv = csdev_to_cti_drvdata(csdev->ect_dev);
 		ctidev = &ctidrv->ctidev;
 		list_for_each_entry(tc, &ctidev->trig_cons, node) {
-			if (tc->con_dev == csdev->ect_dev) {
+			if (tc->con_dev == csdev) {
 				cti_remove_sysfs_link(ctidrv, tc);
 				tc->con_dev = NULL;
 				break;
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index c2174fed263b..6c09be15d60c 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -1254,8 +1254,6 @@ static void coresight_device_release(struct device *dev)
 {
 	struct coresight_device *csdev = to_coresight_device(dev);
 
-	if (cti_assoc_ops && cti_assoc_ops->remove)
-		cti_assoc_ops->remove(csdev);
 	fwnode_handle_put(csdev->dev.fwnode);
 	kfree(csdev->refcnt);
 	kfree(csdev);
@@ -1590,6 +1588,8 @@ void coresight_unregister(struct coresight_device *csdev)
 {
 	etm_perf_del_symlink_sink(csdev);
 	/* Remove references of that device in the topology */
+	if (cti_assoc_ops && cti_assoc_ops->remove)
+		cti_assoc_ops->remove(csdev);
 	coresight_remove_conns(csdev);
 	coresight_clear_default_sink(csdev);
 	coresight_release_platform_data(csdev, csdev->pdata);
-- 
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a Linux Foundation Collaborative Project

