drm/radeon/kms: fix handling of tex lookup disable in cs checker on r2xx

There are cases when multiple texture units have to be enabled,
but not actually used to sample.  This patch checks to see if
the lookup_disable bit is set and if so, skips the texture check.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=25544

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/r100.c

@@ -3180,6 +3180,8 @@ static int r100_cs_track_texture_check(struct radeon_device *rdev,
 	for (u = 0; u < track->num_texture; u++) {
 		if (!track->textures[u].enabled)
 			continue;
+		if (track->textures[u].lookup_disable)
+			continue;
 		robj = track->textures[u].robj;
 		if (robj == NULL) {
 			DRM_ERROR("No texture bound to unit %u\n", u);
@@ -3414,6 +3416,7 @@ void r100_cs_track_clear(struct radeon_device *rdev, struct r100_cs_track *track
 		track->textures[i].robj = NULL;
 		/* CS IB emission code makes sure texture unit are disabled */
 		track->textures[i].enabled = false;
+		track->textures[i].lookup_disable = false;
 		track->textures[i].roundup_w = true;
 		track->textures[i].roundup_h = true;
 		if (track->separate_cube)

drivers/gpu/drm/radeon/r100_track.h

@@ -46,6 +46,7 @@ struct r100_cs_track_texture {
 	unsigned		height_11;
 	bool			use_pitch;
 	bool			enabled;
+	bool                    lookup_disable;
 	bool			roundup_w;
 	bool			roundup_h;
 	unsigned                compress_format;

drivers/gpu/drm/radeon/r200.c

@@ -447,6 +447,8 @@ int r200_packet0_check(struct radeon_cs_parser *p,
 			track->textures[i].width = 1 << ((idx_value >> RADEON_TXFORMAT_WIDTH_SHIFT) & RADEON_TXFORMAT_WIDTH_MASK);
 			track->textures[i].height = 1 << ((idx_value >> RADEON_TXFORMAT_HEIGHT_SHIFT) & RADEON_TXFORMAT_HEIGHT_MASK);
 		}
+		if (idx_value & R200_TXFORMAT_LOOKUP_DISABLE)
+			track->textures[i].lookup_disable = true;
 		switch ((idx_value & RADEON_TXFORMAT_FORMAT_MASK)) {
 		case R200_TXFORMAT_I8:
 		case R200_TXFORMAT_RGB332:

drivers/gpu/drm/radeon/radeon_reg.h

@@ -2836,6 +2836,7 @@
 #       define R200_TXFORMAT_ST_ROUTE_STQ5	(5 << 24)
 #       define R200_TXFORMAT_ST_ROUTE_MASK	(7 << 24)
 #       define R200_TXFORMAT_ST_ROUTE_SHIFT	24
+#       define R200_TXFORMAT_LOOKUP_DISABLE	(1 << 27)
 #       define R200_TXFORMAT_ALPHA_MASK_ENABLE	(1 << 28)
 #       define R200_TXFORMAT_CHROMA_KEY_ENABLE	(1 << 29)
 #       define R200_TXFORMAT_CUBIC_MAP_ENABLE		(1 << 30)