From: Monk Liu <Monk.Liu@amd.com>
Date: Fri, 29 Dec 2017 17:06:41 +0800
Subject: drm/amdgpu: fix&cleanups for wb_clear
Git-commit: f812dec57d55719f5fe1f6fce193561015369363
Patch-mainline: v4.16-rc4
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

fix:
should do right shift on wb before clearing

cleanups:
1,should memset all wb buffer
2,set max wb number to 128 (total 4KB) is big enough

Signed-off-by: Monk Liu <Monk.Liu@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h        |    2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c |    5 +++--
 2 files changed, 4 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1156,7 +1156,7 @@ static inline void amdgpu_set_ib_value(s
 /*
  * Writeback
  */
-#define AMDGPU_MAX_WB 512	/* Reserve at most 512 WB slots for amdgpu-owned rings. */
+#define AMDGPU_MAX_WB 128	/* Reserve at most 128 WB slots for amdgpu-owned rings. */
 
 struct amdgpu_wb {
 	struct amdgpu_bo	*wb_obj;
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -492,7 +492,7 @@ static int amdgpu_device_wb_init(struct
 		memset(&adev->wb.used, 0, sizeof(adev->wb.used));
 
 		/* clear wb memory */
-		memset((char *)adev->wb.wb, 0, AMDGPU_MAX_WB * sizeof(uint32_t));
+		memset((char *)adev->wb.wb, 0, AMDGPU_MAX_WB * sizeof(uint32_t) * 8);
 	}
 
 	return 0;
@@ -530,8 +530,9 @@ int amdgpu_device_wb_get(struct amdgpu_d
  */
 void amdgpu_device_wb_free(struct amdgpu_device *adev, u32 wb)
 {
+	wb >>= 3;
 	if (wb < adev->wb.num_wb)
-		__clear_bit(wb >> 3, adev->wb.used);
+		__clear_bit(wb, adev->wb.used);
 }
 
 /**