[PATCH 1/2] drm/amdgpu: fix reload KMD hang on KIQ

[Monk Liu]

KIQ will hang if we try below steps:
modprobe amdgpu
rmmod amdgpu
modprobe amdgpu sched_hw_submission=4

the cause is that due to KIQ is always living there even
after we unload KMD thus when doing the realod of KMD
KIQ will crash upon its register programed with different
values with the previous configuration (the config
like HQD addr, ring size, is easily changed if we alter
the sched_hw_submission)

the fix is we must inactive KIQ first before touching any
of its registgers

Signed-off-by: Monk Liu <Monk.Liu at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
index db9f1e8..f571e25 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
@@ -6433,6 +6433,9 @@ static int gfx_v10_0_kiq_init_register(struct amdgpu_ring *ring)
 	struct v10_compute_mqd *mqd = ring->mqd_ptr;
 	int j;
 
+	/* activate the queue */
+	WREG32_SOC15(GC, 0, mmCP_HQD_ACTIVE, 0);
+
 	/* disable wptr polling */
 	WREG32_FIELD15(GC, 0, CP_PQ_WPTR_POLL_CNTL, EN, 0);
 
-- 
2.7.4