gpu: nvgpu: Enable ELPG when disabled due to reset

Enable ELPG back whenever ELPG disable is done due to reset or recovery.
Otherwise elpg_refcnt mismatch doesn't engage ELPG correctly

Bug 200156347
Bug 1716764

Change-Id: I9284bb52b32fe911bb8eb260f138b616f4a564be
Signed-off-by: Mahantesh Kumbar <mkumbar@nvidia.com>
Reviewed-on: http://git-master/r/1020617
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: Seshendra Gadagottu <sgadagottu@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>

2 files changed, 11 insertions, 4 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/fifo_gk20a.c b/drivers/gpu/nvgpu/gk20a/fifo_gk20a.c
index 337a9584..769960af 100644
--- a/drivers/gpu/nvgpu/gk20a/fifo_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/fifo_gk20a.c
@@ -793,6 +793,8 @@ void gk20a_fifo_reset_engine(struct gk20a *g, u32 engine_id)
                         /* resetting engine using mc_enable_r() is not
                         enough, we do full init sequence */
                         gk20a_gr_reset(g);
+                if (support_gk20a_pmu(g->dev) && g->elpg_enabled)
+                        gk20a_pmu_enable_elpg(g);
         }
         if (engine_id == top_device_info_type_enum_copy0_v())
                 gk20a_reset(g, mc_enable_ce2_m());
@@ -1099,7 +1101,7 @@ static bool gk20a_fifo_handle_mmu_fault(
                            " deferring channel recovery to channel free");
                 /* clear interrupt */
                 gk20a_writel(g, fifo_intr_mmu_fault_id_r(), fault_id);
-                return verbose;
+                goto exit_enable;
         }
 
         /* clear interrupt */
@@ -1114,6 +1116,7 @@ static bool gk20a_fifo_handle_mmu_fault(
                      gr_gpfifo_ctl_access_enabled_f() |
                      gr_gpfifo_ctl_semaphore_access_enabled_f());
 
+exit_enable:
         /* It is safe to enable ELPG again. */
         if (support_gk20a_pmu(g->dev) && g->elpg_enabled)
                 gk20a_pmu_enable_elpg(g);
diff --git a/drivers/gpu/nvgpu/gk20a/gr_gk20a.h b/drivers/gpu/nvgpu/gk20a/gr_gk20a.h
index 9c37fd02..326b4f96 100644
--- a/drivers/gpu/nvgpu/gk20a/gr_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/gr_gk20a.h
@@ -458,11 +458,15 @@ void gk20a_gr_clear_sm_hww(struct gk20a *g,
 #define gr_gk20a_elpg_protected_call(g, func) \
         ({ \
                 int err = 0; \
-                if (support_gk20a_pmu(g->dev)) \
+                if (support_gk20a_pmu(g->dev) && g->elpg_enabled) {\
                         err = gk20a_pmu_disable_elpg(g); \
-                if (err) return err; \
+                        if (err) { \
+                                gk20a_pmu_enable_elpg(g); \
+                                return err; \
+                        } \
+                } \
                 err = func; \
-                if (support_gk20a_pmu(g->dev)) \
+                if (support_gk20a_pmu(g->dev) && g->elpg_enabled) \
                         gk20a_pmu_enable_elpg(g); \
                 err; \
         })