[PATCH] drm/amdgpu/pm/smu11: fix static fan speed readback

[Alex Deucher]

The xclk needs to be divided by 4.

Fixes: acab02c1af43d3 ("drm/amdgpu/pm/smu11: Fix fan set speed bug")
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c
index 147efe12973c..36dac106ed4b 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c
@@ -1245,7 +1245,11 @@ int smu_v11_0_get_fan_speed_rpm(struct smu_context *smu,
 	if (!tach_period)
 		return -EINVAL;
 
-	crystal_clock_freq = amdgpu_asic_get_xclk(adev);
+	/*
+	 * crystal_clock_freq div by 4 is required since the fan control
+	 * module refers to 25MHz
+	 */
+	crystal_clock_freq = amdgpu_asic_get_xclk(adev) / 4;
 
 	tmp64 = (uint64_t)crystal_clock_freq * 60 * 10000;
 	do_div(tmp64, (tach_period * 8));
-- 
2.29.2