#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! */
value = udev_device_get_sysattr_value(parent, "class");
if (value) {
- unsigned long class;
+ 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;
}
}
return true;
}
+static unsigned get_max_brightness(struct udev_device *device) {
+ int r;
+ const char *max_brightness_str;
+ unsigned max_brightness;
+
+ max_brightness_str = udev_device_get_sysattr_value(device, "max_brightness");
+ if (!max_brightness_str) {
+ 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));
+ return 0;
+ }
+
+ if (max_brightness <= 0) {
+ log_warning("Maximum brightness is 0, ignoring device.");
+ return 0;
+ }
+
+ return max_brightness;
+}
+
+/* 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. */
+static void clamp_brightness(struct udev_device *device, char **value, unsigned max_brightness) {
+ int r;
+ unsigned brightness, new_brightness;
+
+ r = safe_atou(*value, &brightness);
+ if (r < 0) {
+ log_warning("Failed to parse brightness \"%s\": %s", *value, strerror(-r));
+ return;
+ }
+
+ new_brightness = MAX3(brightness, 1U, max_brightness/20);
+ if (new_brightness != brightness) {
+ char *old_value = *value;
+
+ r = asprintf(value, "%u", new_brightness);
+ if (r < 0) {
+ log_oom();
+ return;
+ }
+
+ log_debug("Saved brightness %s too low; increasing to %s.", old_value, *value);
+ free(old_value);
+ }
+}
+
int main(int argc, char *argv[]) {
_cleanup_udev_unref_ struct udev *udev = NULL;
_cleanup_udev_device_unref_ struct udev_device *device = NULL;
- _cleanup_free_ char *saved = NULL, *ss = NULL;
- const char *sysname;
+ _cleanup_free_ char *saved = NULL, *ss = NULL, *escaped_ss = NULL, *escaped_sysname = NULL, *escaped_path_id = NULL;
+ const char *sysname, *path_id;
+ unsigned max_brightness;
int r;
if (argc != 3) {
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;
}
return EXIT_FAILURE;
}
- saved = strjoin("/var/lib/systemd/backlight/", ss, ":", sysname, NULL);
+ /* If max_brightness is 0, then there is no actual backlight
+ * device. This happens on desktops with Asus mainboards
+ * that load the eeepc-wmi module.
+ */
+ max_brightness = get_max_brightness(device);
+ if (max_brightness == 0)
+ return EXIT_SUCCESS;
+
+ escaped_ss = cescape(ss);
+ if (!escaped_ss) {
+ log_oom();
+ return EXIT_FAILURE;
+ }
+
+ escaped_sysname = cescape(sysname);
+ if (!escaped_sysname) {
+ log_oom();
+ return EXIT_FAILURE;
+ }
+
+ path_id = udev_device_get_property_value(device, "ID_PATH");
+ if (path_id) {
+ escaped_path_id = cescape(path_id);
+ if (!escaped_path_id) {
+ log_oom();
+ return EXIT_FAILURE;
+ }
+
+ saved = strjoin("/var/lib/systemd/backlight/", escaped_path_id, ":", escaped_ss, ":", escaped_sysname, NULL);
+ } else
+ saved = strjoin("/var/lib/systemd/backlight/", escaped_ss, ":", escaped_sysname, NULL);
+
if (!saved) {
log_oom();
return EXIT_FAILURE;
* their probing at boot-time might happen in any order. This
* means the validity checking of the device then is not
* reliable, since it might not see other devices conflicting
- * with a specific backlight. To deal with this we will
+ * with a specific backlight. To deal with this, we will
* actively delete backlight state files at shutdown (where
* device probing should be complete), so that the validity
* check at boot time doesn't have to be reliable. */
- if (streq(argv[1], "load")) {
+ if (streq(argv[1], "load") && shall_restore_state()) {
_cleanup_free_ char *value = NULL;
if (!validate_device(udev, device))
return EXIT_FAILURE;
}
+ clamp_brightness(device, &value, max_brightness);
+
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: %s", strerror(-r));
+ log_error("Failed to read system 'brightness' attribute");
return EXIT_FAILURE;
}
~ianmdlvl / elogind.git / blobdiff