drm/radeon: use gart memory for DMA ring tests

Avoids HDP cache flush issues when using vram which can
cause ring test failures on certain boards.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Alexander Fyodorov <halcy@yandex.ru>
Cc: stable@vger.kernel.org

1 files changed, 12 insertions, 9 deletions

diff --git a/drivers/gpu/drm/radeon/r600_dma.c b/drivers/gpu/drm/radeon/r600_dma.c
index a49db830a47f..d9375a361985 100644
--- a/drivers/gpu/drm/radeon/r600_dma.c
+++ b/drivers/gpu/drm/radeon/r600_dma.c
@@ -241,16 +241,19 @@ int r600_dma_ring_test(struct radeon_device *rdev,
 {
         unsigned i;
         int r;
-        void __iomem *ptr = (void *)rdev->vram_scratch.ptr;
+        unsigned index;
         u32 tmp;
+        u64 gpu_addr;
 
-        if (!ptr) {
-                DRM_ERROR("invalid vram scratch pointer\n");
-                return -EINVAL;
-        }
+        if (ring->idx == R600_RING_TYPE_DMA_INDEX)
+                index = R600_WB_DMA_RING_TEST_OFFSET;
+        else
+                index = CAYMAN_WB_DMA1_RING_TEST_OFFSET;
+
+        gpu_addr = rdev->wb.gpu_addr + index;
 
         tmp = 0xCAFEDEAD;
-        writel(tmp, ptr);
+        rdev->wb.wb[index/4] = cpu_to_le32(tmp);
 
         r = radeon_ring_lock(rdev, ring, 4);
         if (r) {
@@ -258,13 +261,13 @@ int r600_dma_ring_test(struct radeon_device *rdev,
                 return r;
         }
         radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_WRITE, 0, 0, 1));
-        radeon_ring_write(ring, rdev->vram_scratch.gpu_addr & 0xfffffffc);
-        radeon_ring_write(ring, upper_32_bits(rdev->vram_scratch.gpu_addr) & 0xff);
+        radeon_ring_write(ring, lower_32_bits(gpu_addr));
+        radeon_ring_write(ring, upper_32_bits(gpu_addr) & 0xff);
         radeon_ring_write(ring, 0xDEADBEEF);
         radeon_ring_unlock_commit(rdev, ring, false);
 
         for (i = 0; i < rdev->usec_timeout; i++) {
-                tmp = readl(ptr);
+                tmp = le32_to_cpu(rdev->wb.wb[index/4]);
                 if (tmp == 0xDEADBEEF)
                         break;
                 DRM_UDELAY(1);