drm/radeon/dpm: fix calculations in si_calculate_leakage_for_v_and_t_formula

Need to make some slight adjustments for the fixed point math to
work properly.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/radeon/si_dpm.c b/drivers/gpu/drm/radeon/si_dpm.c
index 1604a87cf2feda235bed88d0ee2d0e83e46c1d94..cfb444870068d2c894a6299a28c4663f216d2ad4 100644 (file)
--- a/drivers/gpu/drm/radeon/si_dpm.c
+++ b/drivers/gpu/drm/radeon/si_dpm.c
@@ -1765,8 +1765,9 @@ static void si_calculate_leakage_for_v_and_t_formula(const struct ni_leakage_coe
 {
        s64 kt, kv, leakage_w, i_leakage, vddc;
        s64 temperature, t_slope, t_intercept, av, bv, t_ref;
+       s64 tmp;
 
-       i_leakage = drm_int2fixp(ileakage / 100);
+       i_leakage = drm_int2fixp(ileakage) / 100;
        vddc = div64_s64(drm_int2fixp(v), 1000);
        temperature = div64_s64(drm_int2fixp(t), 1000);
 
@@ -1776,8 +1777,9 @@ static void si_calculate_leakage_for_v_and_t_formula(const struct ni_leakage_coe
        bv = div64_s64(drm_int2fixp(coeff->bv), 100000000);
        t_ref = drm_int2fixp(coeff->t_ref);
 
-       kt = drm_fixp_div(drm_fixp_exp(drm_fixp_mul(drm_fixp_mul(t_slope, vddc) + t_intercept, temperature)),
-                         drm_fixp_exp(drm_fixp_mul(drm_fixp_mul(t_slope, vddc) + t_intercept, t_ref)));
+       tmp = drm_fixp_mul(t_slope, vddc) + t_intercept;
+       kt = drm_fixp_exp(drm_fixp_mul(tmp, temperature));
+       kt = drm_fixp_div(kt, drm_fixp_exp(drm_fixp_mul(tmp, t_ref)));
        kv = drm_fixp_mul(av, drm_fixp_exp(drm_fixp_mul(bv, vddc)));
 
        leakage_w = drm_fixp_mul(drm_fixp_mul(drm_fixp_mul(i_leakage, kt), kv), vddc);