1 files changed, 63 insertions, 11 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c b/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c
index 8609e3ae..fea2c774 100644
--- a/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c
+++ b/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c
@@ -25,6 +25,10 @@
 #include <linux/nvmap.h>
 #include <linux/tegra_pm_domains.h>
 #include <linux/platform/tegra/clock.h>
+#include <linux/platform/tegra/dvfs.h>
+#include <linux/platform/tegra/common.h>
+#include <linux/clk/tegra.h>
+#include <mach/tegra_emc.h>
 
 #include "gk20a.h"
 #include "hal_gk20a.h"
@@ -41,6 +45,7 @@ static struct gk20a_platform t132_gk20a_tegra_platform;
 
 struct gk20a_emc_params {
         long bw_ratio;
+        long freq_last_set;
 };
 
 #define MHZ_TO_HZ(x) ((x) * 1000000)
@@ -150,19 +155,26 @@ fail:
  * This function returns the minimum emc clock based on gpu frequency
  */
 
-static long gk20a_tegra_get_emc_rate(struct gk20a *g,
-                              struct gk20a_emc_params *emc_params, long freq)
+static unsigned long gk20a_tegra_get_emc_rate(struct gk20a *g,
+                                struct gk20a_emc_params *emc_params)
 {
-        long hz;
+        unsigned long gpu_freq, gpu_fmax_at_vmin;
+        unsigned long emc_rate, emc_scale;
 
-        freq = HZ_TO_MHZ(freq);
+        gpu_freq = clk_get_rate(g->clk.tegra_clk);
+        gpu_fmax_at_vmin = tegra_dvfs_get_fmax_at_vmin_safe_t(
+                clk_get_parent(g->clk.tegra_clk));
 
-        hz = (freq * emc_params->bw_ratio);
-        hz = (hz * min(g->pmu.load_avg, g->emc3d_ratio)) / 1000;
+        /* When scaling emc, only account for the gpu load below fmax@vmin */
+        if (gpu_freq < gpu_fmax_at_vmin)
+                emc_scale = min(g->pmu.load_avg, g->emc3d_ratio);
+        else
+                emc_scale = g->emc3d_ratio;
 
-        hz = MHZ_TO_HZ(hz);
+        emc_rate =
+                (HZ_TO_MHZ(gpu_freq) * emc_params->bw_ratio * emc_scale) / 1000;
 
-        return hz;
+        return MHZ_TO_HZ(emc_rate);
 }
 
 /*
@@ -178,11 +190,50 @@ static void gk20a_tegra_postscale(struct platform_device *pdev,
         struct gk20a_scale_profile *profile = platform->g->scale_profile;
         struct gk20a_emc_params *emc_params = profile->private_data;
         struct gk20a *g = get_gk20a(pdev);
+        struct clk *emc_clk = platform->clk[2];
+        enum tegra_chipid chip_id = tegra_get_chip_id();
+        unsigned long emc_target;
+        long emc_freq_lower, emc_freq_upper, emc_freq_rounded;
 
-        long after = clk_get_rate(g->clk.tegra_clk);
-        long emc_target = gk20a_tegra_get_emc_rate(g, emc_params, after);
+        emc_target = gk20a_tegra_get_emc_rate(g, emc_params);
 
-        clk_set_rate(platform->clk[2], emc_target);
+        switch (chip_id) {
+        case TEGRA_CHIPID_TEGRA12:
+        case TEGRA_CHIPID_TEGRA13:
+                /* T124 and T132 don't apply any rounding. The resulting
+                 * emc frequency gets implicitly rounded up after issuing
+                 * the clock_set_request.
+                 * So explicitly round up the emc target here to achieve
+                 * the same outcome. */
+                emc_freq_rounded =
+                        tegra_emc_round_rate_updown(emc_target, true);
+                break;
+
+        case TEGRA_CHIPID_TEGRA21:
+                emc_freq_lower = tegra_emc_round_rate_updown(emc_target, false);
+                emc_freq_upper = tegra_emc_round_rate_updown(emc_target, true);
+
+                /* round to the nearest frequency step */
+                if (emc_target < (emc_freq_lower + emc_freq_upper) / 2)
+                        emc_freq_rounded = emc_freq_lower;
+                else
+                        emc_freq_rounded = emc_freq_upper;
+                break;
+
+        case TEGRA_CHIPID_UNKNOWN:
+        default:
+                /* a proper rounding function needs to be implemented
+                 * for emc in t18x */
+                emc_freq_rounded = clk_round_rate(emc_clk, emc_target);
+                break;
+        }
+
+        /* only change the emc clock if new rounded frequency is different
+         * from previously set emc rate */
+        if (emc_freq_rounded != emc_params->freq_last_set) {
+                clk_set_rate(emc_clk, emc_freq_rounded);
+                emc_params->freq_last_set = emc_freq_rounded;
+        }
 }
 
 /*
@@ -384,6 +435,7 @@ static void gk20a_tegra_scale_init(struct platform_device *pdev)
         if (!emc_params)
                 return;
 
+        emc_params->freq_last_set = -1;
         gk20a_tegra_calibrate_emc(pdev, emc_params);
 
         profile->private_data = emc_params;