Comment 46 for bug 703553

I found my mistake, I dumb-thumbed the last bisection.

The patch that's implicated now makes much more sense, and it;s even specific to the model listed in the bug.

I'll build again with that reverted and have it for testing

Here's the offending patch:

From fa7e0b5ba8551654a6887c5b1678c713c0e9c973 Mon Sep 17 00:00:00 2001
From: Alex Deucher <email address hidden>
Date: Mon, 18 Oct 2010 23:54:56 -0400
Subject: [PATCH] drm/radeon/kms: properly compute group_size on 6xx/7xx

BugLink: http://bugs.launchpad.net/bugs/690730

commit 881fe6c1d06bf49f4ab7aef212cdaf66bd059614 upstream.

Needed for tiled surfaces.

Signed-off-by: Alex Deucher <email address hidden>
Signed-off-by: Dave Airlie <email address hidden>
Signed-off-by: Greg Kroah-Hartman <email address hidden>
Signed-off-by: Andi Kleen <email address hidden>
Signed-off-by: Brad Figg <email address hidden>
---
 drivers/gpu/drm/radeon/r600.c | 7 +++++--
 drivers/gpu/drm/radeon/rv770.c | 9 +++++----
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index eddeff3..a40be95 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -1592,8 +1592,11 @@ void r600_gpu_init(struct radeon_device *rdev)
        rdev->config.r600.tiling_npipes = rdev->config.r600.max_tile_pipes;
        rdev->config.r600.tiling_nbanks = 4 << ((ramcfg & NOOFBANK_MASK) >> NOOFBANK_SHIFT);
        tiling_config |= BANK_TILING((ramcfg & NOOFBANK_MASK) >> NOOFBANK_SHIFT);
- tiling_config |= GROUP_SIZE(0);
- rdev->config.r600.tiling_group_size = 256;
+ tiling_config |= GROUP_SIZE((ramcfg & BURSTLENGTH_MASK) >> BURSTLENGTH_SHIFT);
+ if ((ramcfg & BURSTLENGTH_MASK) >> BURSTLENGTH_SHIFT)
+ rdev->config.r600.tiling_group_size = 512;
+ else
+ rdev->config.r600.tiling_group_size = 256;
        tmp = (ramcfg & NOOFROWS_MASK) >> NOOFROWS_SHIFT;
        if (tmp > 3) {
                tiling_config |= ROW_TILING(3);

diff --git a/drivers/gpu/drm/radeon/rv770.c b/drivers/gpu/drm/radeon/rv770.c
index 67e8073..082c380 100644
--- a/drivers/gpu/drm/radeon/rv770.c
+++ b/drivers/gpu/drm/radeon/rv770.c
@@ -627,10 +627,11 @@ static void rv770_gpu_init(struct radeon_device *rdev)
        else
                gb_tiling_config |= BANK_TILING((mc_arb_ramcfg & NOOFBANK_MASK) >> NOOFBANK_SHIFT);
        rdev->config.rv770.tiling_nbanks = 4 << ((gb_tiling_config >> 4) & 0x3);
-
- gb_tiling_config |= GROUP_SIZE(0);
- rdev->config.rv770.tiling_group_size = 256;
-
+ gb_tiling_config |= GROUP_SIZE((mc_arb_ramcfg & BURSTLENGTH_MASK) >> BURSTLENGTH_SHIFT);
+ if ((mc_arb_ramcfg & BURSTLENGTH_MASK) >> BURSTLENGTH_SHIFT)
+ rdev->config.rv770.tiling_group_size = 512;
+ else
+ rdev->config.rv770.tiling_group_size = 256;
        if (((mc_arb_ramcfg & NOOFROWS_MASK) >> NOOFROWS_SHIFT) > 3) {
                gb_tiling_config |= ROW_TILING(3);
                gb_tiling_config |= SAMPLE_SPLIT(3);
--
1.7.0.4