drm/radeon: TTM must be init with cpu-visible VRAM, v2

commit 14eedc32a3c0ec9dd70448a73763ee21feae3111 upstream.

Without this, a bo may get created in the cpu-inaccessible vram.
Before the CP engines get setup, all copies are done via cpu memcpy.

This means that the cpu tries to read from inaccessible memory, fails,
and the radeon module proceeds to disable acceleration.

Doing this has no downsides, as the real VRAM size gets set as soon as the
CP engines get init.

This is a candidate for 3.14 fixes.

v2: Add comment on why the function is used

Signed-off-by: Lauri Kasanen <cand@gmx.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
index 71245d6f34a20c0f64a6eff3057eb6d7ae37f388..84323c943bfc2697f697196afcf6d118d028c5ff 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_ttm.c
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c
@@ -712,6 +712,9 @@ int radeon_ttm_init(struct radeon_device *rdev)
                DRM_ERROR("Failed initializing VRAM heap.\n");
                return r;
        }
+       /* Change the size here instead of the init above so only lpfn is affected */
+       radeon_ttm_set_active_vram_size(rdev, rdev->mc.visible_vram_size);
+
        r = radeon_bo_create(rdev, 256 * 1024, PAGE_SIZE, true,
                             RADEON_GEM_DOMAIN_VRAM,
                             NULL, &rdev->stollen_vga_memory);