nvgpu: gp10b: remove EMC floor when GPU Fmin

Remove EMC floor when GPU frequency is Fmin. At Fmin,
we most likely require a very low memory bandwidth.
At Fmin on load, actmon should sufficiently scale EMC
and hence not bottlenecking GPU.

Bug 1850297

Change-Id: I98b9dae648ea28910d534a9286ce2e9e91ea5fec
Signed-off-by: Cyril Raju <craju@nvidia.com>
Reviewed-on: http://git-master/r/1284572
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Seshendra Gadagottu <sgadagottu@nvidia.com>
Reviewed-by: svccoveritychecker <svccoveritychecker@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/gp10b/platform_gp10b_tegra.c b/drivers/gpu/nvgpu/gp10b/platform_gp10b_tegra.c
index c198f9f1..9f45c929 100644
--- a/drivers/gpu/nvgpu/gp10b/platform_gp10b_tegra.c
+++ b/drivers/gpu/nvgpu/gp10b/platform_gp10b_tegra.c
@@ -312,7 +312,14 @@ static void gp10b_tegra_postscale(struct device *pdev,
 
         gk20a_dbg_fn("");
         if (profile && !gp10b_tegra_is_railgated(pdev)) {
-                emc_rate = (freq * EMC_BW_RATIO * g->emc3d_ratio) / 1000;
+                unsigned long emc_scale;
+
+                if (freq <= gp10b_freq_table[0])
+                        emc_scale = 0;
+                else
+                        emc_scale = g->emc3d_ratio;
+
+                emc_rate = (freq * EMC_BW_RATIO * emc_scale) / 1000;
 
                 if (emc_rate > tegra_bwmgr_get_max_emc_rate())
                         emc_rate = tegra_bwmgr_get_max_emc_rate();