drm/amdgpu: fix an UMC hw arbitrator bug(v3)

issue:
the UMC6 h/w bug is that when MCLK is doing the switch
in the middle of a page access being preempted by high
priority client (e.g. DISPLAY) then UMC and the mclk switch
would stuck there due to deadlock

how:
fixed by disabling auto PreChg for UMC to avoid high
priority client preempting other client's access on
the same page, thus the deadlock could be avoided

v2:
put the patch in callback of UMC6
v3:
rename the callback to "init_registers"

Signed-off-by: Monk Liu <Monk.Liu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Hawking Zhang <hawking.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/umc_v6_0.c b/drivers/gpu/drm/amd/amdgpu/umc_v6_0.c
new file mode 100644
index 000000000000..0d6b50528d76
--- /dev/null
+++ b/drivers/gpu/drm/amd/amdgpu/umc_v6_0.c
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2019 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+#include "umc_v6_0.h"
+#include "amdgpu.h"
+
+static void umc_v6_0_init_registers(struct amdgpu_device *adev)
+{
+	unsigned i,j;
+
+	for (i = 0; i < 4; i++)
+		for (j = 0; j < 4; j++)
+			WREG32((i*0x100000 + 0x5010c + j*0x2000)/4, 0x1002);
+}
+
+const struct amdgpu_umc_funcs umc_v6_0_funcs = {
+	.init_registers = umc_v6_0_init_registers,
+};