From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	=?UTF-8?q?Timur=20Krist=C3=B3f?= <timur.kristof@gmail.com>,
	=?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>,
	Alex Deucher <alexander.deucher@amd.com>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 176/272] drm/amdgpu: Fix amdgpu_bo_move() when old_mem and new_mem are both GTT
Date: Thu, 20 Aug 2026 16:56:00 +0200
Message-ID: <20260820145236.740742508@linuxfoundation.org>
In-Reply-To: <20260820145231.229664293@linuxfoundation.org>
References: <20260820145231.229664293@linuxfoundation.org>
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5.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Timur Kristóf <timur.kristof@gmail.com>

[ Upstream commit ee94a65f192c05c543b4d3ad7137cd696b5c18fc ]

The UVD code relies on GTT to GTT moves in order to ensure
that its BOs don't cross 256M segments.

Fixes: bfe5e585b44f ("drm/ttm: move last binding into the drivers.")
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 21fd45e5e2628d00b478590bcc3d14d3de5d45b6)
Cc: stable@vger.kernel.org
[ dropped the third `new_mem` argument from `amdgpu_bo_move_notify()` and changed `return 0` to `goto out` to match 5.15's 2-arg prototype and shared epilogue ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c |   17 +++++++++++++++++
 1 file changed, 17 insertions(+)

--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -472,6 +472,15 @@ static int amdgpu_bo_move(struct ttm_buf
 
 	if (new_mem->mem_type == TTM_PL_TT ||
 	    new_mem->mem_type == AMDGPU_PL_PREEMPT) {
+		if (old_mem && (old_mem->mem_type == TTM_PL_TT ||
+				old_mem->mem_type == AMDGPU_PL_PREEMPT)) {
+			r = ttm_bo_wait_ctx(bo, ctx);
+			if (r)
+				return r;
+
+			amdgpu_ttm_backend_unbind(bo->bdev, bo->ttm);
+		}
+
 		r = amdgpu_ttm_backend_bind(bo->bdev, bo->ttm, new_mem);
 		if (r)
 			return r;
@@ -505,6 +514,14 @@ static int amdgpu_bo_move(struct ttm_buf
 		ttm_resource_free(bo, &bo->resource);
 		ttm_bo_assign_mem(bo, new_mem);
 		goto out;
+	}
+	if ((old_mem->mem_type == TTM_PL_TT ||
+	     old_mem->mem_type == AMDGPU_PL_PREEMPT) &&
+	    (new_mem->mem_type == TTM_PL_TT ||
+	     new_mem->mem_type == AMDGPU_PL_PREEMPT)) {
+		ttm_resource_free(bo, &bo->resource);
+		ttm_bo_assign_mem(bo, new_mem);
+		goto out;
 	}
 
 	if (old_mem->mem_type == AMDGPU_PL_GDS ||