Commit 58a11d30dee0ab11dfb0437c9af976754f2c1671
2019-12-30T13:21:47
Fixed bug 4920 - Wider support for seconds of battery life left on Linux platforms using sys interface Murad On my system, SDL_GetPowerInfo() returns -1 seconds of battery life left. I have quickly investigated that in my case SDL uses sys interface to get battery data. It tries to read "time_to_empty_now" file which is not always present. However, it is still possible to calculate remaining lifetime using "energy_now" and "power_now" files. This is what my simple patch (included as attachment) tries to accomplish. Best wishes.
diff --git a/src/power/linux/SDL_syspower.c b/src/power/linux/SDL_syspower.c
index 9aa93b4..0fc209c 100644
--- a/src/power/linux/SDL_syspower.c
+++ b/src/power/linux/SDL_syspower.c
@@ -451,6 +451,8 @@ SDL_GetPowerInfo_Linux_sys_class_power_supply(SDL_PowerState *state, int *second
SDL_PowerState st;
int secs;
int pct;
+ int energy;
+ int power;
if ((SDL_strcmp(name, ".") == 0) || (SDL_strcmp(name, "..") == 0)) {
continue; /* skip these, of course. */
@@ -492,11 +494,16 @@ SDL_GetPowerInfo_Linux_sys_class_power_supply(SDL_PowerState *state, int *second
pct = (pct > 100) ? 100 : pct; /* clamp between 0%, 100% */
}
- if (!read_power_file(base, name, "time_to_empty_now", str, sizeof (str))) {
- secs = -1;
- } else {
+ if (read_power_file(base, name, "time_to_empty_now", str, sizeof (str))) {
secs = SDL_atoi(str);
secs = (secs <= 0) ? -1 : secs; /* 0 == unknown */
+ } else if (st == SDL_POWERSTATE_ON_BATTERY) {
+ /* energy is Watt*hours and power is Watts */
+ energy = (read_power_file(base, name, "energy_now", str, sizeof (str))) ? SDL_atoi(str) : -1;
+ power = (read_power_file(base, name, "power_now", str, sizeof (str))) ? SDL_atoi(str) : -1;
+ secs = (energy >= 0 && power > 0) ? (3600LL * energy) / power : -1;
+ } else {
+ secs = -1;
}
/*