我正在尝试通过 xbacklight 更改背光，但这不起作用。虽然
xbacklight -set X
原因
xbacklight -get
返回X，真实显示器背光不变。
XF86MonBrightnessDown (fn+some-key) 也无法工作，尽管它之前可能可以工作。
我该如何进一步调试这个问题？
我尝试跟踪 xbacklight 调用，包括输出，但我无法从中得到任何结果。
有没有办法通过 xrandr 来做到这一点，或者有没有更低级别的方法？
execve("/usr/bin/xbacklight", ["xbacklight", "-set", "30"], [/* 34 vars */]) = 0
brk(0) = 0x8c8000
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f7e5679d000
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=95291, ...}) = 0
mmap(NULL, 95291, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f7e56785000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/usr/lib/x86_64-linux-gnu/libxcb-randr.so.0", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\300[\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=55568, ...}) = 0
mmap(NULL, 2150696, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f7e56371000
mprotect(0x7f7e5637d000, 2097152, PROT_NONE) = 0
mmap(0x7f7e5657d000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0xc000) = 0x7f7e5657d000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/usr/lib/x86_64-linux-gnu/libxcb-util.so.0", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\220&\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=30848, ...}) = 0
mmap(NULL, 2126112, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f7e56169000
mprotect(0x7f7e5616f000, 2093056, PROT_NONE) = 0
mmap(0x7f7e5636e000, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x5000) = 0x7f7e5636e000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/usr/lib/x86_64-linux-gnu/libxcb.so.1", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\340\234\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=138016, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f7e56784000
mmap(NULL, 2233352, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f7e55f47000
mprotect(0x7f7e55f68000, 2093056, PROT_NONE) = 0
mmap(0x7f7e56167000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x20000) = 0x7f7e56167000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\34\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1738176, ...}) = 0
mmap(NULL, 3844640, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f7e55b9c000
mprotect(0x7f7e55d3e000, 2093056, PROT_NONE) = 0
mmap(0x7f7e55f3d000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1a1000) = 0x7f7e55f3d000
mmap(0x7f7e55f43000, 14880, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f7e55f43000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/usr/lib/x86_64-linux-gnu/libXau.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\20\20\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=14544, ...}) = 0
mmap(NULL, 2109744, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f7e55998000
mprotect(0x7f7e5599b000, 2093056, PROT_NONE) = 0
mmap(0x7f7e55b9a000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x2000) = 0x7f7e55b9a000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/usr/lib/x86_64-linux-gnu/libXdmcp.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\340\22\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=20648, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f7e56783000
mmap(NULL, 2115888, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f7e55793000
mprotect(0x7f7e55798000, 2093056, PROT_NONE) = 0
mmap(0x7f7e55997000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x4000) = 0x7f7e55997000
close(3) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f7e56782000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f7e56781000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f7e56780000
arch_prctl(ARCH_SET_FS, 0x7f7e56781700) = 0
mprotect(0x7f7e55f3d000, 16384, PROT_READ) = 0
mprotect(0x7f7e55b9a000, 4096, PROT_READ) = 0
mprotect(0x7f7e56167000, 4096, PROT_READ) = 0
mprotect(0x7f7e5636e000, 8192, PROT_READ) = 0
mprotect(0x7f7e5657d000, 4096, PROT_READ) = 0
mprotect(0x7f7e5679f000, 4096, PROT_READ) = 0
munmap(0x7f7e56785000, 95291) = 0
brk(0) = 0x8c8000
brk(0x8e9000) = 0x8e9000
socket(PF_LOCAL, SOCK_STREAM|SOCK_CLOEXEC, 0) = 3
connect(3, {sa_family=AF_LOCAL, sun_path=@"/tmp/.X11-unix/X0"}, 20) = 0
getpeername(3, {sa_family=AF_LOCAL, sun_path=@"/tmp/.X11-unix/X0"}, [20]) = 0
uname({sys="Linux", node="debian-mini", ...}) = 0
access("/home/myuser/.Xauthority", R_OK) = 0
open("/home/myuser/.Xauthority", O_RDONLY) = 4
fstat(4, {st_mode=S_IFREG|0600, st_size=0, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f7e5679c000
read(4, "", 4096) = 0
close(4) = 0
munmap(0x7f7e5679c000, 4096) = 0
fcntl(3, F_GETFL) = 0x2 (flags O_RDWR)
fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0
fcntl(3, F_SETFD, FD_CLOEXEC) = 0
poll([{fd=3, events=POLLIN|POLLOUT}], 1, 4294967295) = 1 ([{fd=3, revents=POLLOUT}])
writev(3, [{"l\0\v\0\0\0\0\0\0\0\0\0", 12}, {"", 0}], 2) = 12
recvfrom(3, 0x8cd320, 8, 0, 0, 0) = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}], 1, 4294967295) = 1 ([{fd=3, revents=POLLIN}])
recvfrom(3, "\1\0\v\0\0\0{\0", 8, 0, NULL, NULL) = 8
recvfrom(3, " \20\261\0\0\0 \1\377\377\37\0\0\1\0\0\24\0\377\377\1\7\0\0 \10\377\0\0\0\0"..., 492, 0, NULL, NULL) = 492
poll([{fd=3, events=POLLIN|POLLOUT}], 1, 4294967295) = 1 ([{fd=3, revents=POLLOUT}])
writev(3, [{"b\0\4\0\5\0\0\0RANDR\0\0\0", 16}], 1) = 16
poll([{fd=3, events=POLLIN}], 1, 4294967295) = 1 ([{fd=3, revents=POLLIN}])
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"\1\0\1\0\0\0\0\0\1\214Y\223\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", 4096}], msg_controllen=0, msg_flags=0}, 0) = 32
poll([{fd=3, events=POLLIN|POLLOUT}], 1, 4294967295) = 1 ([{fd=3, revents=POLLOUT}])
writev(3, [{"\214\0\3\0\1\0\0\0\2\0\0\0", 12}], 1) = 12
poll([{fd=3, events=POLLIN}], 1, 4294967295) = 1 ([{fd=3, revents=POLLIN}])
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"\1\0\2\0\0\0\0\0\1\0\0\0\2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", 4096}], msg_controllen=0, msg_flags=0}, 0) = 32
poll([{fd=3, events=POLLIN|POLLOUT}], 1, 4294967295) = 1 ([{fd=3, revents=POLLOUT}])
writev(3, [{"\20\1\5\0\t\0\0\0Backlight\0\0\0\20\1\5\0\t\0\0\0BACK"..., 40}], 1) = 40
poll([{fd=3, events=POLLIN}], 1, 4294967295) = 1 ([{fd=3, revents=POLLIN}])
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"\1\0\3\0\0\0\0\0M\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 4096}], msg_controllen=0, msg_flags=0}, 0) = 64
poll([{fd=3, events=POLLIN|POLLOUT}], 1, 4294967295) = 1 ([{fd=3, revents=POLLOUT}])
writev(3, [{"\214\10\2\0\177\0\0\0", 8}], 1) = 8
poll([{fd=3, events=POLLIN}], 1, 4294967295) = 1 ([{fd=3, revents=POLLIN}])
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"\1\0\5\0,\0\0\0\n\276\4\0\n\276\4\0\2\0\2\0\4\0\35\0\0\0\0\0\0\0\0\0"..., 4096}], msg_controllen=0, msg_flags=0}, 0) = 208
poll([{fd=3, events=POLLIN|POLLOUT}], 1, 4294967295) = 1 ([{fd=3, revents=POLLOUT}])
writev(3, [{"\214\17\7\0A\0\0\0M\0\0\0\0\0\0\0\0\0\0\0\4\0\0\0\0\0\0\0", 28}], 1) = 28
poll([{fd=3, events=POLLIN}], 1, 4294967295) = 1 ([{fd=3, revents=POLLIN}])
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"\1 \6\0\1\0\0\0\23\0\0\0\0\0\0\0\1\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 4096}], msg_controllen=0, msg_flags=0}, 0) = 36
poll([{fd=3, events=POLLIN|POLLOUT}], 1, 4294967295) = 1 ([{fd=3, revents=POLLOUT}])
writev(3, [{"\214\v\3\0A\0\0\0M\0\0\0", 12}], 1) = 12
poll([{fd=3, events=POLLIN}], 1, 4294967295) = 1 ([{fd=3, revents=POLLIN}])
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"\1\0\7\0\2\0\0\0\0\1\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 4096}], msg_controllen=0, msg_flags=0}, 0) = 40
poll([{fd=3, events=POLLIN|POLLOUT}], 1, 4294967295) = 1 ([{fd=3, revents=POLLOUT}])
writev(3, [{"\214\17\7\0B\0\0\0M\0\0\0\0\0\0\0\0\0\0\0\4\0\0\0\0\0\0\0", 28}], 1) = 28
poll([{fd=3, events=POLLIN}], 1, 4294967295) = 1 ([{fd=3, revents=POLLIN}])
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"\1\0\10\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", 4096}], msg_controllen=0, msg_flags=0}, 0) = 32
poll([{fd=3, events=POLLIN|POLLOUT}], 1, 4294967295) = 1 ([{fd=3, revents=POLLOUT}])
writev(3, [{"+\0\1\0", 4}], 1) = 4
poll([{fd=3, events=POLLIN}], 1, 4294967295) = 1 ([{fd=3, revents=POLLIN}])
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"\1\1\t\0\0\0\0\0d\t@\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", 4096}], msg_controllen=0, msg_flags=0}, 0) = 32
exit_group(0) = ?
+++ exited with 0 +++
lshw -c 视频：
*-display:0
description: VGA compatible controller
product: Atom Processor D4xx/D5xx/N4xx/N5xx Integrated Graphics Controller
vendor: Intel Corporation
physical id: 2
bus info: pci@0000:00:02.0
version: 00
width: 32 bits
clock: 33MHz
capabilities: vga_controller bus_master cap_list rom
configuration: driver=i915 latency=0
resources: irq:45 memory:f0200000-f027ffff ioport:18e8(size=8) memory:d0000000-dfffffff memory:f0000000-f00fffff
*-display:1 UNCLAIMED
description: Display controller
product: Atom Processor D4xx/D5xx/N4xx/N5xx Integrated Graphics Controller
vendor: Intel Corporation
physical id: 2.1
bus info: pci@0000:00:02.1
version: 00
width: 32 bits
clock: 33MHz
capabilities: bus_master cap_list
configuration: latency=0
resources: memory:f0280000-f02fffff
答案1
正如评论中所建议的，我使用了通过 获得的显卡和驱动程序信息lshw -c video来缩小搜索范围。
$ls /sys/class/backlight/
ideapad
intel_backlight
使用ideapad，这似乎是系统默认的，没有效果，但使用intel_backlight却有：
$echo 1000 | sudo tee /sys/class/backlight/intel_backlight/brightness
1000
我通过以下方式发现了最大亮度：
$cat /sys/class/backlight/intel_backlight/max_brightness
13046
后来，我找到了一个解决方案，让xbacklight和可能的其他工具切换到intel_backlight：
#in /etc/default/grub add acpi_backlight=vendor to GRUB_CMDLINE_LINUX_DEFAULT
GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi_osi=Linux acpi_backlight=vendor"
$sudo update-grub