X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fbacklight%2Fbacklight.c;h=c79ad6520c9f8668f0992c51d7506790f23e8726;hp=ce0385b08c4df67c5b533f8205b787189012937d;hb=e066e1dcc6912bcd160a8f75cb67660d267f988e;hpb=3cadce7d33e263ec7a6a83c00c11144930258b22

diff --git a/src/backlight/backlight.c b/src/backlight/backlight.c
index ce0385b08..c79ad6520 100644
--- a/src/backlight/backlight.c
+++ b/src/backlight/backlight.c
@@ -24,6 +24,7 @@
 #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;
@@ -50,7 +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! */
 
@@ -67,7 +68,8 @@ static struct udev_device *find_pci_or_platform_parent(struct udev_device *devic
                         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;
                         }
 
@@ -175,7 +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;
                 }
 
@@ -184,7 +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;
                 }
         }
@@ -199,13 +205,18 @@ static unsigned get_max_brightness(struct udev_device *device) {
 
         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_errno(r, "Failed to parse 'max_brightness' \"%s\": %m", max_brightness_str);
+                return 0;
+        }
+
+        if (max_brightness <= 0) {
+                log_warning("Maximum brightness is 0, ignoring device.");
                 return 0;
         }
 
@@ -214,19 +225,27 @@ static unsigned get_max_brightness(struct udev_device *device) {
 
 /* 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) {
-                log_warning("Failed to parse brightness \"%s\": %s", *value, strerror(-r));
+                log_warning_errno(r, "Failed to parse brightness \"%s\": %m", *value);
                 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;
 
@@ -236,7 +255,11 @@ static void clamp_brightness(struct udev_device *device, char **value, unsigned
                         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);
         }
 }
@@ -262,7 +285,7 @@ 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_errno(r, "Failed to create backlight directory /var/lib/systemd/backlight: %m");
                 return EXIT_FAILURE;
         }
 
@@ -274,7 +297,7 @@ 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;
         }
 
@@ -295,7 +318,7 @@ int main(int argc, char *argv[]) {
         device = udev_device_new_from_subsystem_sysname(udev, ss, sysname);
         if (!device) {
                 if (errno != 0)
-                        log_error("Failed to get backlight or LED device '%s:%s': %m", ss, sysname);
+                        log_error_errno(errno, "Failed to get backlight or LED device '%s:%s': %m", ss, sysname);
                 else
                         log_oom();
 
@@ -348,8 +371,12 @@ int main(int argc, char *argv[]) {
          * device probing should be complete), so that the validity
          * check at boot time doesn't have to be reliable. */
 
-        if (streq(argv[1], "load") && shall_restore_state()) {
+        if (streq(argv[1], "load")) {
                 _cleanup_free_ char *value = NULL;
+                const char *clamp;
+
+                if (!shall_restore_state())
+                        return EXIT_SUCCESS;
 
                 if (!validate_device(udev, device))
                         return EXIT_SUCCESS;
@@ -360,15 +387,17 @@ int main(int argc, char *argv[]) {
                         if (r == -ENOENT)
                                 return EXIT_SUCCESS;
 
-                        log_error("Failed to read %s: %s", saved, strerror(-r));
+                        log_error_errno(r, "Failed to read %s: %m", saved);
                         return EXIT_FAILURE;
                 }
 
-                clamp_brightness(device, &value, max_brightness);
+                clamp = udev_device_get_property_value(device, "ID_BACKLIGHT_CLAMP");
+                if (!clamp || parse_boolean(clamp) != 0) /* default to clamping */
+                        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_errno(r, "Failed to write system 'brightness' attribute: %m");
                         return EXIT_FAILURE;
                 }
 
@@ -382,13 +411,13 @@ int main(int argc, char *argv[]) {
 
                 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;
                 }
 
                 r = write_string_file(saved, value);
                 if (r < 0) {
-                        log_error("Failed to write %s: %s", saved, strerror(-r));
+                        log_error_errno(r, "Failed to write %s: %m", saved);
                         return EXIT_FAILURE;
                 }