gpu: nvgpu: gm20b: write gpccs start only once

Writing start bit twice can confuse falcon and
results in random behavior.

Bug 200040021

Change-Id: I62eb8e4632ac4fc471d931155471084ee0f9d0a4
Signed-off-by: Vijayakumar <vsubbu@nvidia.com>
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/gpu/nvgpu/gm20b/gr_gm20b.c b/drivers/gpu/nvgpu/gm20b/gr_gm20b.c
index 6bf0ed27..1256d4a6 100644
--- a/drivers/gpu/nvgpu/gm20b/gr_gm20b.c
+++ b/drivers/gpu/nvgpu/gm20b/gr_gm20b.c
@@ -666,9 +666,11 @@ static int gr_gm20b_load_ctxsw_ucode_segments(struct gk20a *g, u64 addr_base,
         gk20a_writel(g, reg_offset + gr_fecs_bootvec_r(),
                         gr_fecs_bootvec_vec_f(segments->boot_entry));
 
-        /* Write to CPUCTL to start the falcon */
-        gk20a_writel(g, reg_offset + gr_fecs_cpuctl_r(),
-                        gr_fecs_cpuctl_startcpu_f(0x01));
+        /* start the falcon immediately if PRIV security is disabled*/
+        if (!g->ops.privsecurity) {
+                gk20a_writel(g, reg_offset + gr_fecs_cpuctl_r(),
+                                gr_fecs_cpuctl_startcpu_f(0x01));
+        }
 
         return 0;
 }