picnoir/Systemd
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

backlight: use current brightness if no saved value to trigger clamping (#8526)

Browse source 
This reads current brightness value in case it has not yet been
saved. This results in the brightness properly being clamped.
This commit is contained in:
Sebastian Reichel 2018-03-28 13:32:27 +02:00 committed by Lennart Poettering
parent ce9aa31496
commit 4432b94135
1 changed files with 41 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

47
src/backlight/backlight.c
View file

@ -269,6 +269,25 @@ static void clamp_brightness(struct udev_device *device, char **value, unsigned
}
}
static bool shall_clamp(struct udev_device *d) {
const char *s;
int r;
assert(d);
s = udev_device_get_property_value(d, "ID_BACKLIGHT_CLAMP");
if (!s)
return true;
r = parse_boolean(s);
if (r < 0) {
log_debug_errno(r, "Failed to parse ID_BACKLIGHT_CLAMP property, ignoring: %m");
return true;
}
return r;
}
int main(int argc, char *argv[]) {
_cleanup_udev_unref_ struct udev *udev = NULL;
_cleanup_udev_device_unref_ struct udev_device *device = NULL;
@ -369,7 +388,7 @@ int main(int argc, char *argv[]) {
if (streq(argv[1], "load")) {
_cleanup_free_ char *value = NULL;
const char *clamp;
bool clamp;
if (shall_restore_state() == 0)
return EXIT_SUCCESS;
@ -377,18 +396,34 @@ int main(int argc, char *argv[]) {
if (!validate_device(udev, device))
return EXIT_SUCCESS;
r = read_one_line_file(saved, &value);
if (r < 0) {
clamp = shall_clamp(device);
if (r == -ENOENT)
r = read_one_line_file(saved, &value);
if (r == -ENOENT) {
const char *curval;
/* Fallback to clamping current brightness or exit early if
* clamping is not supported/enabled. */
if (!clamp)
return EXIT_SUCCESS;
curval = udev_device_get_sysattr_value(device, "brightness");
if (!curval) {
log_warning("Failed to read 'brightness' attribute.");
return EXIT_FAILURE;
}
value = strdup(curval);
if (!value) {
log_oom();
return EXIT_FAILURE;
}
} else if (r < 0) {
log_error_errno(r, "Failed to read %s: %m", saved);
return EXIT_FAILURE;
}
clamp = udev_device_get_property_value(device, "ID_BACKLIGHT_CLAMP");
if (!clamp || parse_boolean(clamp) != 0) /* default to clamping */
if (clamp)
clamp_brightness(device, &value, max_brightness);
r = udev_device_set_sysattr_value(device, "brightness", value);