[PATCH] drm/amdgpu: no rlcg read access in SRIOV case for gfx v9

[Guchun Chen]

Fall back to MMIO to read registers as rlcg read is not
available for gfx v9 in SRIOV configration. Otherwise,
gmc_v9_0_flush_gpu_tlb will always complain timeout and
finally breaks driver load.

Fixes: 0dc4a7e75581("drm/amdgpu: switch to get_rlcg_reg_access_flag for gfx9")
Signed-off-by: Guchun Chen <guchun.chen at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
index e1288901beb6..a3274fa1c7e4 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
@@ -37,6 +37,16 @@
 		vf2pf_info->ucode_info[ucode].version = ver; \
 	} while (0)
 
+static bool amdgpu_virt_is_rlcg_read_supported(struct amdgpu_device *adev)
+{
+	/* rlcg read is not support in SRIOV with gfx v9 */
+	if ((adev->ip_versions[MP0_HWIP][0] == IP_VERSION(9, 0, 0)) ||
+		(adev->ip_versions[GC_HWIP][0] == IP_VERSION(9, 4, 1)))
+		return false;
+
+	return true;
+}
+
 bool amdgpu_virt_mmio_blocked(struct amdgpu_device *adev)
 {
 	/* By now all MMIO pages except mailbox are blocked */
@@ -957,7 +967,8 @@ u32 amdgpu_sriov_rreg(struct amdgpu_device *adev,
 	u32 rlcg_flag;
 
 	if (!amdgpu_sriov_runtime(adev) &&
-	    amdgpu_virt_get_rlcg_reg_access_flag(adev, acc_flags, hwip, false, &rlcg_flag))
+		amdgpu_virt_is_rlcg_read_supported(adev) &&
+		amdgpu_virt_get_rlcg_reg_access_flag(adev, acc_flags, hwip, false, &rlcg_flag))
 		return amdgpu_virt_rlcg_reg_rw(adev, offset, 0, rlcg_flag);
 
 	if (acc_flags & AMDGPU_REGS_NO_KIQ)
-- 
2.17.1