[PATCH] drm/radeon: fix backend map setup on 1 RB trinity boards

[alexdeucher at gmail.com]

From: Alex Deucher <alexander.deucher at amd.com>

Need to adjust the backend map depending on which RB is
enabled.  This is the trinity equivalent of:
f7eb97300832f4fe5fe916c5d84cd2e25169330e

Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Cc: stable at vger.kernel.org
---
 drivers/gpu/drm/radeon/ni.c |   21 ++++++++++++++++-----
 1 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/radeon/ni.c b/drivers/gpu/drm/radeon/ni.c
index 367b7a1..b3521c4e 100644
--- a/drivers/gpu/drm/radeon/ni.c
+++ b/drivers/gpu/drm/radeon/ni.c
@@ -625,11 +625,22 @@ static void cayman_gpu_init(struct radeon_device *rdev)
 	WREG32(DMA_TILING_CONFIG + DMA0_REGISTER_OFFSET, gb_addr_config);
 	WREG32(DMA_TILING_CONFIG + DMA1_REGISTER_OFFSET, gb_addr_config);
 
-	tmp = gb_addr_config & NUM_PIPES_MASK;
-	tmp = r6xx_remap_render_backend(rdev, tmp,
-					rdev->config.cayman.max_backends_per_se *
-					rdev->config.cayman.max_shader_engines,
-					CAYMAN_MAX_BACKENDS, disabled_rb_mask);
+	if ((rdev->config.cayman.max_backends_per_se == 1) &&
+	    (rdev->flags & RADEON_IS_IGP)) {
+		if ((disabled_rb_mask & 3) == 1) {
+			/* RB0 disabled, RB1 enabled */
+			tmp = 0x11111111;
+		} else {
+			/* RB1 disabled, RB0 enabled */
+			tmp = 0x00000000;
+		}
+	} else {
+		tmp = gb_addr_config & NUM_PIPES_MASK;
+		tmp = r6xx_remap_render_backend(rdev, tmp,
+						rdev->config.cayman.max_backends_per_se *
+						rdev->config.cayman.max_shader_engines,
+						CAYMAN_MAX_BACKENDS, disabled_rb_mask);
+	}
 	WREG32(GB_BACKEND_MAP, tmp);
 
 	cgts_tcc_disable = 0xffff0000;
-- 
1.7.7.5