1 files changed, 43 insertions, 0 deletions
diff --git a/sys-power/upower/files/upower-0.99.12-fix-power_now-energy_rate-readings.patch b/sys-power/upower/files/upower-0.99.12-fix-power_now-energy_rate-readings.patch
new file mode 100644
index 000000000000..c3dd864a6b1d
--- /dev/null
+++ b/sys-power/upower/files/upower-0.99.12-fix-power_now-energy_rate-readings.patch
@@ -0,0 +1,43 @@
+From 2949136b152e94aa3b57da5130bcb9022724debe Mon Sep 17 00:00:00 2001
+From: Philipp Zabel <p.zabel@pengutronix.de>
+Date: Thu, 17 Jun 2021 18:14:53 +0200
+Subject: [PATCH] linux: Fix < 0.01 W energy-rate readings from power_now sysfs
+ property
+
+Currently, if a power supplies' power_now sysfs file reports discharge
+rates < 0.01 W, the code will try to calculate the discharge rate from
+the legacy sysfs files. On new kernels where those don't exist, this
+produces wrong results.
+
+For example, on a dual-battery Thinkpad T450s, while the external
+battery is discharging, the internal battery reports power_now = 0,
+but the corresponding upower energy-rate field incorrectly reads
+about 2.3 W.
+
+This patch fixes the issue by falling back to the legacy code only if
+the legacy current_now sysfs file exists.
+
+Closes: #7, #44
+---
+ src/linux/up-device-supply.c | 5 +++--
+ 1 file changed, 3 insertions(+), 2 deletions(-)
+
+diff --git a/src/linux/up-device-supply.c b/src/linux/up-device-supply.c
+index 3ebbd88..4236ce4 100644
+--- a/src/linux/up-device-supply.c
++++ b/src/linux/up-device-supply.c
+@@ -682,8 +682,9 @@ up_device_supply_refresh_battery (UpDeviceSupply *supply,
+ 	state = up_device_supply_get_state (native);
+ 
+ 	/* this is the new value in uW */
+-	energy_rate = fabs (g_udev_device_get_sysfs_attr_as_double_uncached (native, "power_now") / 1000000.0);
+-	if (energy_rate < 0.01) {
++	if (g_udev_device_has_sysfs_attr (native, "power_now")) {
++		energy_rate = fabs (g_udev_device_get_sysfs_attr_as_double_uncached (native, "power_now") / 1000000.0);
++	} else {
+ 		gdouble charge_full;
+ 
+ 		/* convert charge to energy */
+-- 
+GitLab
+