#include "fileio.h"
#include "libudev.h"
#include "udev-util.h"
+#include "def.h"
static struct udev_device *find_pci_or_platform_parent(struct udev_device *device) {
struct udev_device *parent;
if (!c)
return NULL;
- c += strspn(c, "0123456789");
+ c += strspn(c, DIGITS);
if (*c == '-') {
/* A connector DRM device, let's ignore all but LVDS and eDP! */
unsigned long class = 0;
if (safe_atolu(value, &class) < 0) {
- log_warning("Cannot parse PCI class %s of device %s:%s.", value, subsystem, sysname);
+ log_warning("Cannot parse PCI class %s of device %s:%s.",
+ value, subsystem, sysname);
return NULL;
}
if (same_device(parent, other_parent)) {
/* Both have the same PCI parent, that means
* we are out. */
- log_debug("Skipping backlight device %s, since backlight device %s is on same PCI device and, takes precedence.", udev_device_get_sysname(device), udev_device_get_sysname(other));
+ log_debug("Skipping backlight device %s, since device %s is on same PCI device and takes precedence.",
+ udev_device_get_sysname(device),
+ udev_device_get_sysname(other));
return false;
}
/* The other is connected to the platform bus
* and we are a PCI device, that also means we
* are out. */
- log_debug("Skipping backlight device %s, since backlight device %s is a platform device and takes precedence.", udev_device_get_sysname(device), udev_device_get_sysname(other));
+ log_debug("Skipping backlight device %s, since device %s is a platform device and takes precedence.",
+ udev_device_get_sysname(device),
+ udev_device_get_sysname(other));
return false;
}
}
max_brightness_str = udev_device_get_sysattr_value(device, "max_brightness");
if (!max_brightness_str) {
- log_warning("Failed to read max_brightness attribute");
+ log_warning("Failed to read 'max_brightness' attribute.");
return 0;
}
r = safe_atou(max_brightness_str, &max_brightness);
if (r < 0) {
- log_warning("Failed to parse max_brightness \"%s\": %s", max_brightness_str, strerror(-r));
+ log_warning("Failed to parse 'max_brightness' \"%s\": %s", max_brightness_str, strerror(-r));
+ return 0;
+ }
+
+ if (max_brightness <= 0) {
+ log_warning("Maximum brightness is 0, ignoring device.");
return 0;
}
/* Some systems turn the backlight all the way off at the lowest levels.
* clamp_brightness clamps the saved brightness to at least 1 or 5% of
- * max_brightness. This avoids preserving an unreadably dim screen, which
- * would otherwise force the user to disable state restoration. */
+ * max_brightness in case of 'backlight' subsystem. This avoids preserving
+ * an unreadably dim screen, which would otherwise force the user to
+ * disable state restoration. */
static void clamp_brightness(struct udev_device *device, char **value, unsigned max_brightness) {
int r;
- unsigned brightness, new_brightness;
+ unsigned brightness, new_brightness, min_brightness;
+ const char *subsystem;
r = safe_atou(*value, &brightness);
if (r < 0) {
return;
}
- new_brightness = MAX3(brightness, 1U, max_brightness/20);
+ subsystem = udev_device_get_subsystem(device);
+ if (streq_ptr(subsystem, "backlight"))
+ min_brightness = MAX(1U, max_brightness/20);
+ else
+ min_brightness = 0;
+
+ new_brightness = CLAMP(brightness, min_brightness, max_brightness);
if (new_brightness != brightness) {
char *old_value = *value;
return;
}
- log_debug("Saved brightness %s too low; increasing to %s.", old_value, *value);
+ log_info("Saved brightness %s %s to %s.", old_value,
+ new_brightness > brightness ?
+ "too low; increasing" : "too high; decreasing",
+ *value);
+
free(old_value);
}
}
r = mkdir_p("/var/lib/systemd/backlight", 0755);
if (r < 0) {
- log_error("Failed to create backlight directory: %s", strerror(-r));
+ log_error("Failed to create backlight directory /var/lib/systemd/backlight: %s",
+ strerror(-r));
return EXIT_FAILURE;
}
sysname = strchr(argv[2], ':');
if (!sysname) {
- log_error("Requires pair of subsystem and sysname for specifying backlight device.");
+ log_error("Requires a subsystem and sysname pair specifying a backlight device.");
return EXIT_FAILURE;
}
r = udev_device_set_sysattr_value(device, "brightness", value);
if (r < 0) {
- log_error("Failed to write system attribute: %s", strerror(-r));
+ log_error("Failed to write system 'brightness' attribute: %s",
+ strerror(-r));
return EXIT_FAILURE;
}
value = udev_device_get_sysattr_value(device, "brightness");
if (!value) {
- log_error("Failed to read system attribute");
+ log_error("Failed to read system 'brightness' attribute");
return EXIT_FAILURE;
}