[PATCH] drm/radeon: Fix rs400_gpu_init for ATI mobility radeon Xpress 200M

[Richard Thier]

num_gb_pipes was set to a wrong value using r420_pipe_config

This have lead to HyperZ glitches on fast Z clearing.

See: https://bugs.freedesktop.org/show_bug.cgi?id=110897

Signed-off-by: Richard Thier <u9vata at gmail.com>
---
 drivers/gpu/drm/radeon/r300.c  |  3 ++-
 drivers/gpu/drm/radeon/rs400.c | 21 +++++++++++++++++++--
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/radeon/r300.c b/drivers/gpu/drm/radeon/r300.c
index 652126f..6724c15 100644
--- a/drivers/gpu/drm/radeon/r300.c
+++ b/drivers/gpu/drm/radeon/r300.c
@@ -355,7 +355,8 @@ int r300_mc_wait_for_idle(struct radeon_device *rdev)
 	return -1;
 }
 
-static void r300_gpu_init(struct radeon_device *rdev)
+/* rs400_gpu_init also calls this! */
+void r300_gpu_init(struct radeon_device *rdev)
 {
 	uint32_t gb_tile_config, tmp;
 
diff --git a/drivers/gpu/drm/radeon/rs400.c b/drivers/gpu/drm/radeon/rs400.c
index 4121209..4117572 100644
--- a/drivers/gpu/drm/radeon/rs400.c
+++ b/drivers/gpu/drm/radeon/rs400.c
@@ -32,6 +32,9 @@
 #include "radeon_asic.h"
 #include "rs400d.h"
 
+/* Needed for rs400_gpu_init that forwards to the r300 one */
+void r300_gpu_init(struct radeon_device *rdev);
+
 /* This files gather functions specifics to : rs400,rs480 */
 static int rs400_debugfs_pcie_gart_info_init(struct radeon_device *rdev);
 
@@ -252,8 +255,22 @@ int rs400_mc_wait_for_idle(struct radeon_device *rdev)
 
 static void rs400_gpu_init(struct radeon_device *rdev)
 {
-	/* FIXME: is this correct ? */
-	r420_pipes_init(rdev);
+	/* Earlier code was calling r420_pipes_init and then
+	 * rs400_mc_wait_for_idle(rdev). The problem is that 
+	 * at least on my Mobility Radeon Xpress 200M RC410 card
+	 * that ends up in this code path ends up num_gb_pipes == 3
+	 * while the card seems to have only one pipe. With the
+	 * r420 pipe initialization method.
+	 *
+	 * Problems shown up as HyperZ glitches, see:
+	 * https://bugs.freedesktop.org/show_bug.cgi?id=110897
+	 *
+	 * Delegating initialization to r300 code seems to work
+	 * and results in proper pipe numbers. The rs400 cards 
+	 * are said to be not r400, but r300 kind of cards.
+	 */
+	r300_gpu_init(rdev);
+
 	if (rs400_mc_wait_for_idle(rdev)) {
 		pr_warn("rs400: Failed to wait MC idle while programming pipes. Bad things might happen. %08x\n",
 			RREG32(RADEON_MC_STATUS));
-- 
2.21.0