drm/amdkfd: Initialize only amdkfd's assigned pipelines

This patch fixes a bug in the initialization of the pipelines. The
init_pipelines() function was called with a constant value of 0 in the
first_pipe argument. This is an error because amdkfd doesn't handle pipe 0.

The correct way is to pass the value that get_first_pipe() returns as the
argument for first_pipe.

This bug appeared in 3.19 (first version with amdkfd) and it causes around 15%
drop in CPU performance of Kaveri (A10-7850).

v2: Don't set get_first_pipe() as inline because it calls BUG_ON()

Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
Cc: stable@vger.kernel.org
Tested-by: Michel Dänzer <michel.daenzer@amd.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index b3589d0..1b58f33 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -62,9 +62,9 @@ enum KFD_MQD_TYPE get_mqd_type_from_queue_type(enum kfd_queue_type type)
 	return KFD_MQD_TYPE_CP;
 }
 
-static inline unsigned int get_first_pipe(struct device_queue_manager *dqm)
+unsigned int get_first_pipe(struct device_queue_manager *dqm)
 {
-	BUG_ON(!dqm);
+	BUG_ON(!dqm || !dqm->dev);
 	return dqm->dev->shared_resources.first_compute_pipe;
 }