[PATCH 4.16 084/279] drm/amdkfd: fix clock counter retrieval for node without GPU

[Greg Kroah-Hartman]

4.16-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andres Rodriguez <andres.rodriguez@xxxxxxx>

[ Upstream commit 1cf6cc74bbeb85bb87c3ca3f3df97a283c3aa737 ]

Currently if a user requests clock counters for a node without a GPU
resource we will always return EINVAL.

Instead if no GPU resource is attached, fill the gpu_clock_counter
argument with zeroes so that we may proceed and return valid CPU
counters.

Signed-off-by: Andres Rodriguez <andres.rodriguez@xxxxxxx>
Signed-off-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
Reviewed-by: Oded Gabbay <oded.gabbay@xxxxxxxxx>
Signed-off-by: Oded Gabbay <oded.gabbay@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/amd/amdkfd/kfd_chardev.c |   13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -748,12 +748,13 @@ static int kfd_ioctl_get_clock_counters(
 	struct timespec64 time;
 
 	dev = kfd_device_by_id(args->gpu_id);
-	if (dev == NULL)
-		return -EINVAL;
-
-	/* Reading GPU clock counter from KGD */
-	args->gpu_clock_counter =
-		dev->kfd2kgd->get_gpu_clock_counter(dev->kgd);
+	if (dev)
+		/* Reading GPU clock counter from KGD */
+		args->gpu_clock_counter =
+			dev->kfd2kgd->get_gpu_clock_counter(dev->kgd);
+	else
+		/* Node without GPU resource */
+		args->gpu_clock_counter = 0;
 
 	/* No access to rdtsc. Using raw monotonic time */
 	getrawmonotonic64(&time);