drm/radeon/kms: allow rendering while no colorbuffer is set on r300
Because hardware cannot disable all colorbuffers directly to do depth-only
rendering, a user should:
- disable reading from a colorbuffer in blending
- disable fastfill
- set the color channel mask to 0 to prevent writing to a colorbuffer
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
index 84e5df7..7172746 100644
--- a/drivers/gpu/drm/radeon/r100.c
+++ b/drivers/gpu/drm/radeon/r100.c
@@ -2881,6 +2881,10 @@
for (i = 0; i < track->num_cb; i++) {
if (track->cb[i].robj == NULL) {
+ if (!(track->fastfill || track->color_channel_mask ||
+ track->blend_read_enable)) {
+ continue;
+ }
DRM_ERROR("[drm] No buffer for color buffer %d !\n", i);
return -EINVAL;
}
diff --git a/drivers/gpu/drm/radeon/r100_track.h b/drivers/gpu/drm/radeon/r100_track.h
index 7188c37..b27a699 100644
--- a/drivers/gpu/drm/radeon/r100_track.h
+++ b/drivers/gpu/drm/radeon/r100_track.h
@@ -67,13 +67,15 @@
unsigned immd_dwords;
unsigned num_arrays;
unsigned max_indx;
+ unsigned color_channel_mask;
struct r100_cs_track_array arrays[11];
struct r100_cs_track_cb cb[R300_MAX_CB];
struct r100_cs_track_cb zb;
struct r100_cs_track_texture textures[R300_TRACK_MAX_TEXTURE];
bool z_enabled;
bool separate_cube;
-
+ bool fastfill;
+ bool blend_read_enable;
};
int r100_cs_track_check(struct radeon_device *rdev, struct r100_cs_track *track);
diff --git a/drivers/gpu/drm/radeon/r300.c b/drivers/gpu/drm/radeon/r300.c
index 83490c2..6a5d117 100644
--- a/drivers/gpu/drm/radeon/r300.c
+++ b/drivers/gpu/drm/radeon/r300.c
@@ -992,6 +992,18 @@
}
ib[idx] = idx_value + ((u32)reloc->lobj.gpu_offset);
break;
+ case 0x4e0c:
+ /* RB3D_COLOR_CHANNEL_MASK */
+ track->color_channel_mask = idx_value;
+ break;
+ case 0x4d1c:
+ /* ZB_BW_CNTL */
+ track->fastfill = !!(idx_value & (1 << 2));
+ break;
+ case 0x4e04:
+ /* RB3D_BLENDCNTL */
+ track->blend_read_enable = !!(idx_value & (1 << 2));
+ break;
case 0x4be8:
/* valid register only on RV530 */
if (p->rdev->family == CHIP_RV530)