This was non-trivial to get right because commits
c23bc382ef0e ("coresight: etm4x: Refactor probing routine") and
5214b563588e ("coresight: etm4x: Add support for sysreg only devices")
changed the code flow considerably. With this change the driver can be
built again.

Fixes: 0573d3fa4864 ("Merge branch 'devel-stable' of git://git.armlinux.org.uk/~rmk/linux-arm into char-misc-next")
Signed-off-by: Uwe Kleine-König <redacted>
---
On Fri, Feb 05, 2021 at 12:07:09PM +0100, Greg Kroah-Hartman wrote:

On Fri, Feb 05, 2021 at 11:56:15AM +0100, Uwe Kleine-König wrote:

quoted

I didn't compile test, but I'm willing to bet your resolution is wrong.
You have no return statement in etm4_remove_dev() but its return type is
int and etm4_remove_amba() still returns int but should return void.

Can you send a patch to fix this up?

Sure, here it comes. As I'm unsure if you want to squash it into the
merge or want to keep it separate I crafted a commit message. If you
prefer squashing feel free to do so.

This change corresponds to the merge resolution I suggested before.

Best regards
Uwe

 drivers/hwtracing/coresight/coresight-etm4x-core.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index bc55b261af23..c8ecd91e289e 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c

@@ -1906,15 +1906,16 @@ static int __exit etm4_remove_dev(struct etmv4_drvdata *drvdata)
 	cpus_read_unlock();
 
 	coresight_unregister(drvdata->csdev);
+
+	return 0;
 }
 
-static int __exit etm4_remove_amba(struct amba_device *adev)
+static void __exit etm4_remove_amba(struct amba_device *adev)
 {
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(&adev->dev);
 
 	if (drvdata)
-		return etm4_remove_dev(drvdata);
-	return 0;
+		etm4_remove_dev(drvdata);
 }
 
 static int __exit etm4_remove_platform_dev(struct platform_device *pdev)

-- 
2.29.2