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-rw-r--r--src/backlight/backlight.c417
1 files changed, 237 insertions, 180 deletions
diff --git a/src/backlight/backlight.c b/src/backlight/backlight.c
index b2032ad..2de6c20 100644
--- a/src/backlight/backlight.c
+++ b/src/backlight/backlight.c
@@ -11,7 +11,6 @@
#include "escape.h"
#include "fileio.h"
#include "main-func.h"
-#include "mkdir.h"
#include "parse-util.h"
#include "percent-util.h"
#include "pretty-print.h"
@@ -20,6 +19,7 @@
#include "string-util.h"
#include "strv.h"
#include "terminal-util.h"
+#include "verbs.h"
#define PCI_CLASS_GRAPHICS_CARD 0x30000
@@ -91,8 +91,8 @@ static int has_multiple_graphics_cards(void) {
}
static int find_pci_or_platform_parent(sd_device *device, sd_device **ret) {
- const char *subsystem, *sysname, *value;
sd_device *parent;
+ const char *s;
int r;
assert(device);
@@ -102,34 +102,29 @@ static int find_pci_or_platform_parent(sd_device *device, sd_device **ret) {
if (r < 0)
return r;
- r = sd_device_get_subsystem(parent, &subsystem);
- if (r < 0)
- return r;
-
- r = sd_device_get_sysname(parent, &sysname);
- if (r < 0)
- return r;
+ if (device_in_subsystem(parent, "drm")) {
- if (streq(subsystem, "drm")) {
- const char *c;
+ r = sd_device_get_sysname(parent, &s);
+ if (r < 0)
+ return r;
- c = startswith(sysname, "card");
- if (!c)
+ s = startswith(s, "card");
+ if (!s)
return -ENODATA;
- c += strspn(c, DIGITS);
- if (*c == '-' && !STARTSWITH_SET(c, "-LVDS-", "-Embedded DisplayPort-", "-eDP-"))
+ s += strspn(s, DIGITS);
+ if (*s == '-' && !STARTSWITH_SET(s, "-LVDS-", "-Embedded DisplayPort-", "-eDP-"))
/* A connector DRM device, let's ignore all but LVDS and eDP! */
return -EOPNOTSUPP;
- } else if (streq(subsystem, "pci") &&
- sd_device_get_sysattr_value(parent, "class", &value) >= 0) {
+ } else if (device_in_subsystem(parent, "pci") &&
+ sd_device_get_sysattr_value(parent, "class", &s)) {
+
unsigned long class;
- r = safe_atolu(value, &class);
+ r = safe_atolu(s, &class);
if (r < 0)
- return log_warning_errno(r, "Cannot parse PCI class '%s' of device %s:%s: %m",
- value, subsystem, sysname);
+ return log_device_warning_errno(parent, r, "Cannot parse PCI class '%s': %m", s);
/* Graphics card */
if (class == PCI_CLASS_GRAPHICS_CARD) {
@@ -137,7 +132,7 @@ static int find_pci_or_platform_parent(sd_device *device, sd_device **ret) {
return 0;
}
- } else if (streq(subsystem, "platform")) {
+ } else if (device_in_subsystem(parent, "platform")) {
*ret = parent;
return 0;
}
@@ -176,7 +171,7 @@ static int same_device(sd_device *a, sd_device *b) {
static int validate_device(sd_device *device) {
_cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *enumerate = NULL;
- const char *v, *sysname, *subsystem;
+ const char *v, *sysname;
sd_device *parent;
int r;
@@ -184,7 +179,7 @@ static int validate_device(sd_device *device) {
/* Verify whether we should actually care for a specific backlight device. For backlight devices
* there might be multiple ways to access the same control: "firmware" (i.e. ACPI), "platform"
- * (i.e. via the machine's EC) and "raw" (via the graphics card). In general we should prefer
+ * (i.e. via the machine's EC), and "raw" (via the graphics card). In general we should prefer
* "firmware" (i.e. ACPI) or "platform" access over "raw" access, in order not to confuse the
* BIOS/EC, and compatibility with possible low-level hotkey handling of screen brightness. The
* kernel will already make sure to expose only one of "firmware" and "platform" for the same
@@ -195,11 +190,8 @@ static int validate_device(sd_device *device) {
if (r < 0)
return log_device_debug_errno(device, r, "Failed to get sysname: %m");
- r = sd_device_get_subsystem(device, &subsystem);
- if (r < 0)
- return log_device_debug_errno(device, r, "Failed to get subsystem: %m");
- if (!streq(subsystem, "backlight"))
- return true;
+ if (!device_in_subsystem(device, "backlight"))
+ return true; /* We assume LED device is always valid. */
r = sd_device_get_sysattr_value(device, "type", &v);
if (r < 0)
@@ -211,15 +203,12 @@ static int validate_device(sd_device *device) {
if (r < 0)
return log_device_debug_errno(device, r, "Failed to find PCI or platform parent: %m");
- r = sd_device_get_subsystem(parent, &subsystem);
- if (r < 0)
- return log_device_debug_errno(parent, r, "Failed to get subsystem: %m");
-
if (DEBUG_LOGGING) {
- const char *s = NULL;
+ const char *s = NULL, *subsystem = NULL;
(void) sd_device_get_syspath(parent, &s);
- log_device_debug(device, "Found %s parent device: %s", subsystem, strna(s));
+ (void) sd_device_get_subsystem(parent, &subsystem);
+ log_device_debug(device, "Found %s parent device: %s", strna(subsystem), strna(s));
}
r = sd_device_enumerator_new(&enumerate);
@@ -246,7 +235,7 @@ static int validate_device(sd_device *device) {
if (r < 0)
return log_debug_errno(r, "Failed to add sysattr match: %m");
- if (streq(subsystem, "pci")) {
+ if (device_in_subsystem(parent, "pci")) {
r = has_multiple_graphics_cards();
if (r < 0)
return log_debug_errno(r, "Failed to check if the system has multiple graphics cards: %m");
@@ -254,8 +243,8 @@ static int validate_device(sd_device *device) {
/* If the system has multiple graphics cards, then we cannot associate platform
* devices on non-PCI bus (especially WMI bus) with PCI devices. Let's ignore all
* backlight devices that do not have the same parent PCI device. */
- log_debug("Found multiple graphics cards on PCI bus. "
- "Skipping to associate platform backlight devices on non-PCI bus.");
+ log_debug("Found multiple graphics cards on PCI bus; "
+ "skipping deduplication of platform backlight devices not on PCI bus.");
r = sd_device_enumerator_add_match_parent(enumerate, parent);
if (r < 0)
@@ -264,7 +253,6 @@ static int validate_device(sd_device *device) {
}
FOREACH_DEVICE(enumerate, other) {
- const char *other_subsystem;
sd_device *other_parent;
/* OK, so there's another backlight device, and it's a platform or firmware device.
@@ -289,13 +277,7 @@ static int validate_device(sd_device *device) {
return false;
}
- r = sd_device_get_subsystem(other_parent, &other_subsystem);
- if (r < 0) {
- log_device_debug_errno(other_parent, r, "Failed to get subsystem, ignoring: %m");
- continue;
- }
-
- if (streq(other_subsystem, "platform") && streq(subsystem, "pci")) {
+ if (device_in_subsystem(other_parent, "platform") && device_in_subsystem(parent, "pci")) {
/* The other is connected to the platform bus and we are a PCI device, that also means we are out. */
if (DEBUG_LOGGING) {
const char *other_sysname = NULL, *other_type = NULL;
@@ -313,7 +295,8 @@ static int validate_device(sd_device *device) {
return true;
}
-static int get_max_brightness(sd_device *device, unsigned *ret) {
+static int read_max_brightness(sd_device *device, unsigned *ret) {
+ unsigned max_brightness;
const char *s;
int r;
@@ -324,11 +307,22 @@ static int get_max_brightness(sd_device *device, unsigned *ret) {
if (r < 0)
return log_device_warning_errno(device, r, "Failed to read 'max_brightness' attribute: %m");
- r = safe_atou(s, ret);
+ r = safe_atou(s, &max_brightness);
if (r < 0)
return log_device_warning_errno(device, r, "Failed to parse 'max_brightness' \"%s\": %m", s);
- return 0;
+ /* 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. */
+ if (max_brightness == 0) {
+ log_device_warning(device, "Maximum brightness is 0, ignoring device.");
+ *ret = 0;
+ return 0;
+ }
+
+ log_device_debug(device, "Maximum brightness is %u", max_brightness);
+
+ *ret = max_brightness;
+ return 1; /* valid max brightness */
}
static int clamp_brightness(
@@ -339,8 +333,6 @@ static int clamp_brightness(
unsigned *brightness) {
unsigned new_brightness, min_brightness;
- const char *subsystem;
- int r;
assert(device);
assert(brightness);
@@ -350,14 +342,9 @@ static int clamp_brightness(
* avoids preserving an unreadably dim screen, which would otherwise force the user to disable
* state restoration. */
- r = sd_device_get_subsystem(device, &subsystem);
- if (r < 0)
- return log_device_warning_errno(device, r, "Failed to get device subsystem: %m");
-
- if (streq(subsystem, "backlight"))
- min_brightness = MAX(1U, (unsigned) ((double) max_brightness * percent / 100));
- else
- min_brightness = 0;
+ min_brightness = (unsigned) ((double) max_brightness * percent / 100);
+ if (device_in_subsystem(device, "backlight"))
+ min_brightness = MAX(1U, min_brightness);
new_brightness = CLAMP(*brightness, min_brightness, max_brightness);
if (new_brightness != *brightness)
@@ -372,19 +359,28 @@ static int clamp_brightness(
return 0;
}
-static bool shall_clamp(sd_device *d, unsigned *ret) {
- const char *s;
+static bool shall_clamp(sd_device *device, unsigned *ret) {
+ const char *property, *s;
+ unsigned default_percent;
int r;
- assert(d);
+ assert(device);
assert(ret);
- r = sd_device_get_property_value(d, "ID_BACKLIGHT_CLAMP", &s);
+ if (device_in_subsystem(device, "backlight")) {
+ property = "ID_BACKLIGHT_CLAMP";
+ default_percent = 5;
+ } else {
+ property = "ID_LEDS_CLAMP";
+ default_percent = 0;
+ }
+
+ r = sd_device_get_property_value(device, property, &s);
if (r < 0) {
if (r != -ENOENT)
- log_device_debug_errno(d, r, "Failed to get ID_BACKLIGHT_CLAMP property, ignoring: %m");
- *ret = 5; /* defaults to 5% */
- return true;
+ log_device_debug_errno(device, r, "Failed to get %s property, ignoring: %m", property);
+ *ret = default_percent;
+ return default_percent > 0;
}
r = parse_boolean(s);
@@ -395,9 +391,9 @@ static bool shall_clamp(sd_device *d, unsigned *ret) {
r = parse_percent(s);
if (r < 0) {
- log_device_debug_errno(d, r, "Failed to parse ID_BACKLIGHT_CLAMP property, ignoring: %m");
- *ret = 5;
- return true;
+ log_device_debug_errno(device, r, "Failed to parse %s property, ignoring: %m", property);
+ *ret = default_percent;
+ return default_percent > 0;
}
*ret = r;
@@ -405,18 +401,14 @@ static bool shall_clamp(sd_device *d, unsigned *ret) {
}
static int read_brightness(sd_device *device, unsigned max_brightness, unsigned *ret_brightness) {
- const char *subsystem, *value;
+ const char *value;
unsigned brightness;
int r;
assert(device);
assert(ret_brightness);
- r = sd_device_get_subsystem(device, &subsystem);
- if (r < 0)
- return log_device_debug_errno(device, r, "Failed to get subsystem: %m");
-
- if (streq(subsystem, "backlight")) {
+ if (device_in_subsystem(device, "backlight")) {
r = sd_device_get_sysattr_value(device, "actual_brightness", &value);
if (r == -ENOENT) {
log_device_debug_errno(device, r, "Failed to read 'actual_brightness' attribute, "
@@ -463,154 +455,219 @@ use_brightness:
return 0;
}
-static int run(int argc, char *argv[]) {
- _cleanup_(sd_device_unrefp) sd_device *device = NULL;
- _cleanup_free_ char *escaped_ss = NULL, *escaped_sysname = NULL, *escaped_path_id = NULL;
- const char *sysname, *path_id, *ss, *saved;
- unsigned max_brightness, brightness;
+static int build_save_file_path(sd_device *device, char **ret) {
+ _cleanup_free_ char *escaped_subsystem = NULL, *escaped_sysname = NULL, *path = NULL;
+ const char *s;
int r;
- log_setup();
+ assert(device);
+ assert(ret);
- if (argv_looks_like_help(argc, argv))
- return help();
+ r = sd_device_get_subsystem(device, &s);
+ if (r < 0)
+ return log_device_error_errno(device, r, "Failed to get subsystem: %m");
- if (argc != 3)
- return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "This program requires two arguments.");
+ escaped_subsystem = cescape(s);
+ if (!escaped_subsystem)
+ return log_oom();
- if (!STR_IN_SET(argv[1], "load", "save"))
- return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown verb %s.", argv[1]);
+ r = sd_device_get_sysname(device, &s);
+ if (r < 0)
+ return log_device_error_errno(device, r, "Failed to get sysname: %m");
- umask(0022);
+ escaped_sysname = cescape(s);
+ if (!escaped_sysname)
+ return log_oom();
- r = mkdir_p("/var/lib/systemd/backlight", 0755);
- if (r < 0)
- return log_error_errno(r, "Failed to create backlight directory /var/lib/systemd/backlight: %m");
+ if (sd_device_get_property_value(device, "ID_PATH", &s) >= 0) {
+ _cleanup_free_ char *escaped_path_id = cescape(s);
+ if (!escaped_path_id)
+ return log_oom();
- sysname = strchr(argv[2], ':');
- if (!sysname)
- return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Requires a subsystem and sysname pair specifying a backlight device.");
+ path = strjoin("/var/lib/systemd/backlight/", escaped_path_id, ":", escaped_subsystem, ":", escaped_sysname);
+ } else
+ path = strjoin("/var/lib/systemd/backlight/", escaped_subsystem, ":", escaped_sysname);
+ if (!path)
+ return log_oom();
- ss = strndupa_safe(argv[2], sysname - argv[2]);
+ *ret = TAKE_PTR(path);
+ return 0;
+}
- sysname++;
+static int read_saved_brightness(sd_device *device, unsigned *ret) {
+ _cleanup_free_ char *path = NULL, *value = NULL;
+ int r;
- if (!STR_IN_SET(ss, "backlight", "leds"))
- return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Not a backlight or LED device: '%s:%s'", ss, sysname);
+ assert(device);
+ assert(ret);
+
+ r = build_save_file_path(device, &path);
+ if (r < 0)
+ return r;
- r = sd_device_new_from_subsystem_sysname(&device, ss, sysname);
+ r = read_one_line_file(path, &value);
if (r < 0) {
- bool ignore = r == -ENODEV;
+ if (r != -ENOENT)
+ log_device_error_errno(device, r, "Failed to read %s: %m", path);
+ return r;
+ }
- /* Some drivers, e.g. for AMD GPU, removes acpi backlight device soon after it is added.
- * See issue #21997. */
- log_full_errno(ignore ? LOG_DEBUG : LOG_ERR, r,
- "Failed to get backlight or LED device '%s:%s'%s: %m",
- ss, sysname, ignore ? ", ignoring" : "");
- return ignore ? 0 : r;
+ r = safe_atou(value, ret);
+ if (r < 0) {
+ log_device_warning_errno(device, r,
+ "Failed to parse saved brightness '%s', removing %s.",
+ value, path);
+ (void) unlink(path);
+ return r;
}
- /* 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. */
- if (get_max_brightness(device, &max_brightness) < 0)
- return 0;
+ log_device_debug(device, "Using saved brightness %u.", *ret);
+ return 0;
+}
- if (max_brightness == 0) {
- log_device_warning(device, "Maximum brightness is 0, ignoring device.");
- return 0;
- }
+static int device_new_from_arg(const char *s, sd_device **ret) {
+ _cleanup_(sd_device_unrefp) sd_device *device = NULL;
+ _cleanup_free_ char *subsystem = NULL;
+ const char *sysname;
+ int r;
- log_device_debug(device, "Maximum brightness is %u", max_brightness);
+ assert(s);
+ assert(ret);
- escaped_ss = cescape(ss);
- if (!escaped_ss)
- return log_oom();
+ sysname = strchr(s, ':');
+ if (!sysname)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "Requires a subsystem and sysname pair specifying a backlight or LED device.");
- escaped_sysname = cescape(sysname);
- if (!escaped_sysname)
+ subsystem = strndup(s, sysname - s);
+ if (!subsystem)
return log_oom();
- if (sd_device_get_property_value(device, "ID_PATH", &path_id) >= 0) {
- escaped_path_id = cescape(path_id);
- if (!escaped_path_id)
- return log_oom();
+ sysname++;
- saved = strjoina("/var/lib/systemd/backlight/", escaped_path_id, ":", escaped_ss, ":", escaped_sysname);
- } else
- saved = strjoina("/var/lib/systemd/backlight/", escaped_ss, ":", escaped_sysname);
+ if (!STR_IN_SET(subsystem, "backlight", "leds"))
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "Not a backlight or LED device: '%s:%s'",
+ subsystem, sysname);
- /* If there are multiple conflicting backlight devices, then 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 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. */
+ r = sd_device_new_from_subsystem_sysname(&device, subsystem, sysname);
+ if (r == -ENODEV) {
+ /* Some drivers, e.g. for AMD GPU, removes acpi backlight device soon after it is added.
+ * See issue #21997. */
+ log_debug_errno(r, "Failed to get backlight or LED device '%s:%s', ignoring: %m", subsystem, sysname);
+ *ret = NULL;
+ return 0;
+ }
+ if (r < 0)
+ return log_error_errno(r, "Failed to get backlight or LED device '%s:%s': %m", subsystem, sysname);
- if (streq(argv[1], "load")) {
- _cleanup_free_ char *value = NULL;
- unsigned percent;
- bool clamp;
+ *ret = TAKE_PTR(device);
+ return 1; /* Found. */
+}
- if (!shall_restore_state())
- return 0;
+static int verb_load(int argc, char *argv[], void *userdata) {
+ _cleanup_(sd_device_unrefp) sd_device *device = NULL;
+ unsigned max_brightness, brightness, percent;
+ bool clamp;
+ int r;
- if (validate_device(device) == 0)
- return 0;
+ assert(argc == 2);
- clamp = shall_clamp(device, &percent);
+ if (!shall_restore_state())
+ return 0;
- r = read_one_line_file(saved, &value);
- if (r < 0 && r != -ENOENT)
- return log_error_errno(r, "Failed to read %s: %m", saved);
- if (r > 0) {
- r = safe_atou(value, &brightness);
- if (r < 0) {
- log_warning_errno(r, "Failed to parse saved brightness '%s', removing %s.",
- value, saved);
- (void) unlink(saved);
- } else {
- log_debug("Using saved brightness %u.", brightness);
- if (clamp)
- (void) clamp_brightness(device, percent, /* saved = */ true, max_brightness, &brightness);
-
- /* Do not fall back to read current brightness below. */
- r = 1;
- }
- }
- if (r <= 0) {
- /* Fallback to clamping current brightness or exit early if clamping is not
- * supported/enabled. */
- if (!clamp)
- return 0;
+ r = device_new_from_arg(argv[1], &device);
+ if (r <= 0)
+ return r;
- r = read_brightness(device, max_brightness, &brightness);
- if (r < 0)
- return log_device_error_errno(device, r, "Failed to read current brightness: %m");
+ r = read_max_brightness(device, &max_brightness);
+ if (r <= 0)
+ return r;
- (void) clamp_brightness(device, percent, /* saved = */ false, max_brightness, &brightness);
- }
+ /* Ignore any errors in validation, and use the device as is. */
+ if (validate_device(device) == 0)
+ return 0;
- r = sd_device_set_sysattr_valuef(device, "brightness", "%u", brightness);
- if (r < 0)
- return log_device_error_errno(device, r, "Failed to write system 'brightness' attribute: %m");
+ clamp = shall_clamp(device, &percent);
- } else if (streq(argv[1], "save")) {
- if (validate_device(device) == 0) {
- (void) unlink(saved);
+ r = read_saved_brightness(device, &brightness);
+ if (r < 0) {
+ /* Fallback to clamping current brightness or exit early if clamping is not
+ * supported/enabled. */
+ if (!clamp)
return 0;
- }
r = read_brightness(device, max_brightness, &brightness);
if (r < 0)
return log_device_error_errno(device, r, "Failed to read current brightness: %m");
- r = write_string_filef(saved, WRITE_STRING_FILE_CREATE, "%u", brightness);
- if (r < 0)
- return log_device_error_errno(device, r, "Failed to write %s: %m", saved);
+ (void) clamp_brightness(device, percent, /* saved = */ false, max_brightness, &brightness);
+ } else if (clamp)
+ (void) clamp_brightness(device, percent, /* saved = */ true, max_brightness, &brightness);
- } else
- assert_not_reached();
+ r = sd_device_set_sysattr_valuef(device, "brightness", "%u", brightness);
+ if (r < 0)
+ return log_device_error_errno(device, r, "Failed to write system 'brightness' attribute: %m");
+
+ return 0;
+}
+
+static int verb_save(int argc, char *argv[], void *userdata) {
+ _cleanup_(sd_device_unrefp) sd_device *device = NULL;
+ _cleanup_free_ char *path = NULL;
+ unsigned max_brightness, brightness;
+ int r;
+
+ assert(argc == 2);
+
+ r = device_new_from_arg(argv[1], &device);
+ if (r <= 0)
+ return r;
+
+ r = read_max_brightness(device, &max_brightness);
+ if (r <= 0)
+ return r;
+
+ r = build_save_file_path(device, &path);
+ if (r < 0)
+ return r;
+
+ /* If there are multiple conflicting backlight devices, then 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 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 (validate_device(device) == 0) {
+ (void) unlink(path);
+ return 0;
+ }
+
+ r = read_brightness(device, max_brightness, &brightness);
+ if (r < 0)
+ return log_device_error_errno(device, r, "Failed to read current brightness: %m");
+
+ r = write_string_filef(path, WRITE_STRING_FILE_CREATE | WRITE_STRING_FILE_MKDIR_0755, "%u", brightness);
+ if (r < 0)
+ return log_device_error_errno(device, r, "Failed to write %s: %m", path);
return 0;
}
+static int run(int argc, char *argv[]) {
+ static const Verb verbs[] = {
+ { "load", 2, 2, VERB_ONLINE_ONLY, verb_load },
+ { "save", 2, 2, VERB_ONLINE_ONLY, verb_save },
+ {}
+ };
+
+ log_setup();
+
+ if (argv_looks_like_help(argc, argv))
+ return help();
+
+ umask(0022);
+
+ return dispatch_verb(argc, argv, verbs, NULL);
+}
+
DEFINE_MAIN_FUNCTION(run);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-15 09:51:41 +0000