drm/radeon/kms: disable VGA rendering engine before taking over VRAM

Before we use any of VRAM, we need to disable the VGA rendering
engine, this render text mode into a graphical framebuffer
for scanout, however it does this on vblank, and can end up
overwriting the GART table and r600 shader objects.

Signed-off-by: Dave Airlie <airlied@redhat.com>

4 files changed, 20 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/avivod.h b/drivers/gpu/drm/radeon/avivod.h
index d4e6e6e4a938..e2b92c445bab 100644
--- a/drivers/gpu/drm/radeon/avivod.h
+++ b/drivers/gpu/drm/radeon/avivod.h
@@ -57,4 +57,13 @@
 #define VGA_RENDER_CONTROL                              0x0300
 #define         VGA_VSTATUS_CNTL_MASK                           0x00030000
 
+/* AVIVO disable VGA rendering */
+static inline void radeon_avivo_vga_render_disable(struct radeon_device *rdev)
+{
+        u32 vga_render;
+        vga_render = RREG32(VGA_RENDER_CONTROL);
+        vga_render &= ~VGA_VSTATUS_CNTL_MASK;
+        WREG32(VGA_RENDER_CONTROL, vga_render);
+}
+
 #endif
diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index 1e1cab5ef1e4..aafdb8edc11d 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -340,6 +340,10 @@ static void r600_mc_resume(struct radeon_device *rdev)
         WREG32(D1VGA_CONTROL, d1vga_control);
         WREG32(D2VGA_CONTROL, d2vga_control);
         WREG32(VGA_RENDER_CONTROL, vga_render_control);
+
+        /* we need to own VRAM, so turn off the VGA renderer here
+         * to stop it overwriting our objects */
+        radeon_avivo_vga_render_disable(rdev);
 }
 
 int r600_mc_init(struct radeon_device *rdev)
diff --git a/drivers/gpu/drm/radeon/rs600.c b/drivers/gpu/drm/radeon/rs600.c
index 6af0331cae08..0e791e26def3 100644
--- a/drivers/gpu/drm/radeon/rs600.c
+++ b/drivers/gpu/drm/radeon/rs600.c
@@ -28,6 +28,7 @@
 #include "drmP.h"
 #include "radeon_reg.h"
 #include "radeon.h"
+#include "avivod.h"
 
 #include "rs600_reg_safe.h"
 
@@ -197,6 +198,8 @@ void rs600_mc_disable_clients(struct radeon_device *rdev)
                        "programming pipes. Bad things might happen.\n");
         }
 
+        radeon_avivo_vga_render_disable(rdev);
+
         tmp = RREG32(AVIVO_D1VGA_CONTROL);
         WREG32(AVIVO_D1VGA_CONTROL, tmp & ~AVIVO_DVGA_CONTROL_MODE_ENABLE);
         tmp = RREG32(AVIVO_D2VGA_CONTROL);
diff --git a/drivers/gpu/drm/radeon/rv770.c b/drivers/gpu/drm/radeon/rv770.c
index 8bab6b4f05d1..47427623a84c 100644
--- a/drivers/gpu/drm/radeon/rv770.c
+++ b/drivers/gpu/drm/radeon/rv770.c
@@ -229,6 +229,10 @@ static void rv770_mc_resume(struct radeon_device *rdev)
         WREG32(D1VGA_CONTROL, d1vga_control);
         WREG32(D2VGA_CONTROL, d2vga_control);
         WREG32(VGA_RENDER_CONTROL, vga_render_control);
+
+        /* we need to own VRAM, so turn off the VGA renderer here
+         * to stop it overwriting our objects */
+        radeon_avivo_vga_render_disable(rdev);
 }