From 31f731af513bb9925d0a29dba34bb4f71141bf91 Mon Sep 17 00:00:00 2001 From: Alex Deucher Date: Tue, 30 Jul 2013 16:56:52 -0400 Subject: [PATCH] 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 --- drivers/gpu/drm/radeon/si_dpm.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/radeon/si_dpm.c b/drivers/gpu/drm/radeon/si_dpm.c index 1604a87cf2fe..cfb444870068 100644 --- 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);