gpu: nvgpu: avoid redundant enable/disable PG

ELPG powergate is refcounted. We should not enable/disable it,
if it's already so. Or it will break the PG disable/enable function.

Bug 200410661

Change-Id: Ife60f373b877d1ffc441578ffa53fe0d4409eba6
Signed-off-by: Daniel Fu <danifu@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1774265
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: svc-misra-checker <svc-misra-checker@nvidia.com>
Reviewed-by: Vinod Gopalakrishnakurup <vinodg@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c b/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c
index ddf2039b..7ec9f5d3 100644
--- a/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c
@@ -232,7 +232,12 @@ int dbg_set_powergate(struct dbg_session_gk20a *dbg_s, bool disable_powergate)
                         return err;
 
                 /*do elpg disable before clock gating */
-                nvgpu_pmu_pg_global_enable(g, false);
+
+                /* we should not disabled it again, if it's already so */
+                if (g->elpg_enabled) {
+                        g->elpg_enabled = false;
+                        nvgpu_pmu_pg_global_enable(g, false);
+                }
 
                 if (g->ops.clock_gating.slcg_gr_load_gating_prod)
                         g->ops.clock_gating.slcg_gr_load_gating_prod(g,
@@ -276,7 +281,12 @@ int dbg_set_powergate(struct dbg_session_gk20a *dbg_s, bool disable_powergate)
                                 slcg_gr_load_gating_prod(g,
                                 g->slcg_enabled);
                 }
-                nvgpu_pmu_pg_global_enable(g, true);
+
+                /* we should not enable it again, if it's already so */
+                if (!g->elpg_enabled) {
+                        g->elpg_enabled = true;
+                        nvgpu_pmu_pg_global_enable(g, true);
+                }
 
                 nvgpu_log(g, gpu_dbg_gpu_dbg | gpu_dbg_fn,
                                         "module idle");