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authorAlex Deucher <alexander.deucher@amd.com>2013-07-30 16:56:52 -0400
committerAlex Deucher <alexander.deucher@amd.com>2013-07-30 17:24:13 -0400
commit31f731af513bb9925d0a29dba34bb4f71141bf91 (patch)
tree55214f3c0abe069b792377f3d8aa0fb4d121e727
parenta838834b2f7cbc09b6319a1fc332c03e4d665b20 (diff)
downloadlinux-31f731af513bb9925d0a29dba34bb4f71141bf91.tar.bz2
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>
-rw-r--r--drivers/gpu/drm/radeon/si_dpm.c8
1 files 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);