X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fbacklight%2Fbacklight.c;h=c708391612a289352d39c9620d22b08b6ee953ca;hp=9ec29f79a40197af00b629f1cad902a2d9b8eeba;hb=c7fdf44d08e1217d40dc092fb90a65978a0f541f;hpb=74df0fca09b3c31ed19e14ba80f996fdff772417 diff --git a/src/backlight/backlight.c b/src/backlight/backlight.c index 9ec29f79a..c70839161 100644 --- a/src/backlight/backlight.c +++ b/src/backlight/backlight.c @@ -24,7 +24,7 @@ #include "fileio.h" #include "libudev.h" #include "udev-util.h" -#include "util.h" +#include "def.h" static struct udev_device *find_pci_or_platform_parent(struct udev_device *device) { struct udev_device *parent; @@ -51,7 +51,7 @@ static struct udev_device *find_pci_or_platform_parent(struct udev_device *devic 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! */ @@ -65,10 +65,11 @@ static struct udev_device *find_pci_or_platform_parent(struct udev_device *devic 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; } @@ -176,7 +177,9 @@ static bool validate_device(struct udev *udev, struct udev_device *device) { 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; } @@ -185,7 +188,9 @@ static bool validate_device(struct udev *udev, struct udev_device *device) { /* 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; } } @@ -193,11 +198,66 @@ static bool validate_device(struct udev *udev, struct udev_device *device) { 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, *escaped_ss = NULL, *escaped_sysname = NULL, *escaped_path_id = NULL; const char *sysname, *path_id; + unsigned max_brightness; int r; if (argc != 3) { @@ -213,7 +273,8 @@ int main(int argc, char *argv[]) { 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; } @@ -225,7 +286,7 @@ int main(int argc, char *argv[]) { 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; } @@ -253,6 +314,14 @@ int main(int argc, char *argv[]) { return EXIT_FAILURE; } + /* 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(); @@ -286,7 +355,7 @@ int main(int argc, char *argv[]) { * 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. */ @@ -307,9 +376,12 @@ int main(int argc, char *argv[]) { 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; } @@ -323,7 +395,7 @@ int main(int argc, char *argv[]) { 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; }