gpu: nvgpu: Do not readback L2 ZBC RAM

Do not read back L2 ZBC RAM. That can conflict with in-flight
transactions causing a live-lock.

Change-Id: I6122af48513b5a4b801202dc611eba58ce86aa4d
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: http://git-master/r/929580
GVS: Gerrit_Virtual_Submit
Reviewed-by: Seshendra Gadagottu <sgadagottu@nvidia.com>
Tested-by: Seshendra Gadagottu <sgadagottu@nvidia.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/ltc_common.c b/drivers/gpu/nvgpu/gk20a/ltc_common.c
index 1c18418c..cc0932d9 100644
--- a/drivers/gpu/nvgpu/gk20a/ltc_common.c
+++ b/drivers/gpu/nvgpu/gk20a/ltc_common.c
@@ -53,9 +53,10 @@ static void gk20a_ltc_set_zbc_color_entry(struct gk20a *g,
 
         for (i = 0;
              i < ltc_ltcs_ltss_dstg_zbc_color_clear_value__size_1_v(); i++) {
-                gk20a_writel_check(g, ltc_ltcs_ltss_dstg_zbc_color_clear_value_r(i),
+                gk20a_writel(g, ltc_ltcs_ltss_dstg_zbc_color_clear_value_r(i),
                              color_val->color_l2[i]);
         }
+        gk20a_readl(g, ltc_ltcs_ltss_dstg_zbc_index_r());
 }
 
 /*
@@ -70,8 +71,10 @@ static void gk20a_ltc_set_zbc_depth_entry(struct gk20a *g,
         gk20a_writel(g, ltc_ltcs_ltss_dstg_zbc_index_r(),
                      ltc_ltcs_ltss_dstg_zbc_index_address_f(real_index));
 
-        gk20a_writel_check(g, ltc_ltcs_ltss_dstg_zbc_depth_clear_value_r(),
+        gk20a_writel(g, ltc_ltcs_ltss_dstg_zbc_depth_clear_value_r(),
                      depth_val->depth);
+
+        gk20a_readl(g, ltc_ltcs_ltss_dstg_zbc_index_r());
 }
 
 static int gk20a_ltc_alloc_phys_cbc(struct gk20a *g,