[SRU][K][PATCH 1/1] drm/amdgpu: Fix for BO move issue

[Timo Aaltonen]

From: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam at amd.com>

BugLink: https://bugs.launchpad.net/bugs/2018470

A user reported a bug on CAPE VERDE system where uvd_v3_1
IP component failed to initialize as there is an issue with
BO move code from one memory to other.

In function amdgpu_mem_visible() called by amdgpu_bo_move(),
when there are no blocks to compare or if we have a single
block then break the loop.

Fixes: 312b4dc11d4f ("drm/amdgpu: Fix VRAM BO swap issue")
Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam at amd.com>
Reviewed-by: Christian König <christian.koenig at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
(cherry picked from commit 8273b4048664fff356fd10059033f0e2f5a422a1)
Signed-off-by: Timo Aaltonen <timo.aaltonen at canonical.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 98014cfccc92..40cfbbfe5436 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -439,6 +439,9 @@ static bool amdgpu_mem_visible(struct amdgpu_device *adev,
 	while (cursor.remaining) {
 		amdgpu_res_next(&cursor, cursor.size);
 
+		if (!cursor.remaining)
+			break;
+
 		/* ttm_resource_ioremap only supports contiguous memory */
 		if (end != cursor.start)
 			return false;
-- 
2.39.2