[PATCH 2/2] drm/amdgpu: handle AMDGPU_IB_FLAG_RESET_GDS_MAX_WAVE_ID on gfx10

[Marek Olšák]

From: Marek Olšák <marek.olsak at amd.com>

Signed-off-by: Marek Olšák <marek.olsak at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
index 6baaa65a1daa..5b807a19bbbf 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
@@ -4257,20 +4257,36 @@ static void gfx_v10_0_ring_emit_ib_gfx(struct amdgpu_ring *ring,
 }
 
 static void gfx_v10_0_ring_emit_ib_compute(struct amdgpu_ring *ring,
 					   struct amdgpu_job *job,
 					   struct amdgpu_ib *ib,
 					   uint32_t flags)
 {
 	unsigned vmid = AMDGPU_JOB_GET_VMID(job);
 	u32 control = INDIRECT_BUFFER_VALID | ib->length_dw | (vmid << 24);
 
+	/* Currently, there is a high possibility to get wave ID mismatch
+	 * between ME and GDS, leading to a hw deadlock, because ME generates
+	 * different wave IDs than the GDS expects. This situation happens
+	 * randomly when at least 5 compute pipes use GDS ordered append.
+	 * The wave IDs generated by ME are also wrong after suspend/resume.
+	 * Those are probably bugs somewhere else in the kernel driver.
+	 *
+	 * Writing GDS_COMPUTE_MAX_WAVE_ID resets wave ID counters in ME and
+	 * GDS to 0 for this ring (me/pipe).
+	 */
+	if (ib->flags & AMDGPU_IB_FLAG_RESET_GDS_MAX_WAVE_ID) {
+		amdgpu_ring_write(ring, PACKET3(PACKET3_SET_CONFIG_REG, 1));
+		amdgpu_ring_write(ring, mmGDS_COMPUTE_MAX_WAVE_ID);
+		amdgpu_ring_write(ring, ring->adev->gds.gds_compute_max_wave_id);
+	}
+
 	amdgpu_ring_write(ring, PACKET3(PACKET3_INDIRECT_BUFFER, 2));
 	BUG_ON(ib->gpu_addr & 0x3); /* Dword align */
 	amdgpu_ring_write(ring,
 #ifdef __BIG_ENDIAN
 				(2 << 0) |
 #endif
 				lower_32_bits(ib->gpu_addr));
 	amdgpu_ring_write(ring, upper_32_bits(ib->gpu_addr));
 	amdgpu_ring_write(ring, control);
 }
@@ -5103,20 +5119,21 @@ static void gfx_v10_0_set_rlc_funcs(struct amdgpu_device *adev)
 	}
 }
 
 static void gfx_v10_0_set_gds_init(struct amdgpu_device *adev)
 {
 	/* init asic gds info */
 	switch (adev->asic_type) {
 	case CHIP_NAVI10:
 	default:
 		adev->gds.gds_size = 0x10000;
+		adev->gds.gds_compute_max_wave_id = 0x4ff;
 		adev->gds.vgt_gs_max_wave_id = 0x3ff;
 		break;
 	}
 
 	adev->gds.gws_size = 64;
 	adev->gds.oa_size = 16;
 }
 
 static void gfx_v10_0_set_user_wgp_inactive_bitmap_per_sh(struct amdgpu_device *adev,
 							  u32 bitmap)
-- 
2.17.1