drm/radeon/kms: rv6xx+ thermal sensor fixes

Some fixes to the thermal sensor code:
- handle negative numbers
- properly handle temp calculation on different asics

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index 1e10e3e2ba2a..650672a0f5ad 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -97,12 +97,16 @@ void r600_irq_disable(struct radeon_device *rdev);
 static void r600_pcie_gen2_enable(struct radeon_device *rdev);
 
 /* get temperature in millidegrees */
-u32 rv6xx_get_temp(struct radeon_device *rdev)
+int rv6xx_get_temp(struct radeon_device *rdev)
 {
         u32 temp = (RREG32(CG_THERMAL_STATUS) & ASIC_T_MASK) >>
                 ASIC_T_SHIFT;
+        int actual_temp = temp & 0xff;
 
-        return temp * 1000;
+        if (temp & 0x100)
+                actual_temp -= 256;
+
+        return actual_temp * 1000;
 }
 
 void r600_pm_get_dynpm_state(struct radeon_device *rdev)