deal with overflow much better

1 files changed, 7 insertions, 0 deletions

diff --git a/devices/ahci.cpp b/devices/ahci.cpp
index 1309a28..3ed5455 100644
--- a/devices/ahci.cpp
+++ b/devices/ahci.cpp
@@ -89,10 +89,14 @@ void ahci::end_measurement(void)
 	}
 
 	p = (end_active - start_active) / (0.001 + end_active + end_partial + end_slumber - start_active - start_partial - start_slumber) * 100.0;
+	if (p < 0)
+		 p = 0;
 	sprintf(powername, "%s-active", name);
 	report_utilization(powername, p);
 
 	p = (end_partial - start_partial) / (0.001 + end_active + end_partial + end_slumber - start_active - start_partial - start_slumber) * 100.0;
+	if (p < 0)
+		 p = 0;
 	sprintf(powername, "%s-partial", name);
 	report_utilization(powername, p);
 }
@@ -104,6 +108,9 @@ double ahci::utilization(void)
 
 	p = (end_partial - start_partial + end_active - start_active) / (0.001 + end_active + end_partial + end_slumber - start_active - start_partial - start_slumber) * 100.0;
 
+	if (p < 0)
+		p = 0;
+
 	return p;
 }