After closing the lid, the MBA 2013 has either 100% or 0% brightness set up. There are NO possible "middle-choices" such as 50% or 25%. This happens EACH time that the MBA goes to sleep.
Do you mean when you close the lid, the MBA goes to sleep, but the brightness is at 100%. Is this correct?
AaronLu, no, behavior is really interesting:
- boot computer from cold
- can adjust brightness fine at this point
- suspend to ram
- wake up
- try to adjust brightness, but there are only two brightness levels available: 100% or 0%.
In the problematic case /sys/class/backlight/acpi_video0/brightness reports the correct values as brightness is changed. But backlight either goes zero or full brightness.
This issue is reported in Arch, Ubuntu and Freedesktop:
I am testing on a MacAir 6,2 (2013). Let me know if I can do any testing. I will try with 3.12-rc5 right now and let you know about the results.
Problem persists with 3.12.0-rc5.
Same here with 3.12.0-rc5.
So this means acpi_video stops working after resume.
Does intel_backlight work before/after resume?
You can test it by echoing some value there, e.g.:
# cd /sys/class/backlight
# cat max_brightness
1024 (an example)
# echo 200 > brightness
see if backlight level changed
# echo 500 > brightness
No it does not work. If you echo a number other than the one which represents the "max_brightness" the screen goes off.
Created attachment 111091 [details]
test brightness with different values and write values to output file
Created attachment 111101 [details]
output of brightness_test.sh before pm-suspend command
Created attachment 111111 [details]
output of brightness_test.sh after pm-suspend command
I attached the test script I have used to test this problem. As GiulioDP mentions, all is fine before the suspend but problem appears after suspend. More detailed:
- bash brightness_test.sh
- screen goes full brightness, 50% brightness, 25% brightness
- copy log file as test_output_before_resume
- suspend with pm-suspend command
- wait a second, resume by pressing a key
- bash brigthness_test.sh
- screen goes full brightness, 0% brightness
- manually increase brightness to full brightness
- copy log file as test_output_after_resume
Please attach acpidump:
# acpidump > acpidump.txt
Do you happen to know this problem? Both acpi_video and intel_backlight's interfaces stop working after resume on Macbook Air 2013.
On 3.12.0-rc5 same both before and after resume:
Table length (0x00000024) is invalid
Could not get ACPI tables, AE_BAD_HEADER
(In reply to Aaron Lu from comment #11)
> Please attach acpidump:
> # acpidump > acpidump.txt
> Hi Jani,
> Do you happen to know this problem? Both acpi_video and intel_backlight's
> interfaces stop working after resume on Macbook Air 2013.
We know the problem, but not the solution I'm afraid: https://bugs.freedesktop.org/show_bug.cgi?id=67454
No luck with 3.12.0-rc6 : (
Two other points hoping they might ring some bells:
Interesting brightness behavior (appears to be the same before/after suspend):
- reduce brightness to zero
- increase brightness by 10% -> OK
- increase brightness by 10% -> brightness increases some, pauses a moment and then increases some more.
VLC video corruption:
- While playing video with VLC player video freezes partially or fully.
- Changing window with alt-tab refreshes the picture.
- Sound plays fine (VLC thinks all is good?)
- Disable "Accelerated video output (overlay)" from settings
- Video plays fine.
I can conduct any other test you need.
What about the acpidump version that is in kernel tree?
$ ls kernel_src_tree/tools/power/acpi
acpidump.8 acpidump.c Makefile
That works, I have attached the files.
Created attachment 111931 [details]
acpidump_before_pm_suspend from kernel source tree
Created attachment 111941 [details]
acpidump_after_pm_suspend from kernel source tree
(In reply to Can Kavaklıoğlu from comment #16)
> That works, I have attached the files.
Please note that I attached results of two separate runs of the acpidump. Both runs produced the same result.
I tried hibernation instead of suspend to ram using pm-hibernate command. Brightness problem does not occur in this case.
Thanks to the fast SSD drive it may (almost) be a replacement for suspending to ram.
No luck with 3.12.0-rc7 : (
I can confirm I am experiencing the same issue on a MacBookAir6,2 running 3.11.6-200.fc19.x86_64.
Also it looks like this is a duplicate: https://bugzilla.kernel.org/show_bug.cgi?id=60707
I also just tested on kernel-3.12.0-0.rc7.git2.1.fc21.x86_64 and I am still experiencing the same issue.
No luck with 3.12.0 : (
I got the same problem on a Macbook Air 6,2 (i5-4250U CPU @ 1.30GHz) with kernel 3.12.0.
Sorry, I am quite new to this kernel bugzilla handling, so please excuse my clumsy question: Why is the status of this bug 'NEEDINFO' for two weeks now? Is Can Kavaklıoğlu's acpidump not sufficient?
I concur. Please advise on debugging/troubleshooting steps. Those of us who have this hardware would like to help test.
No more info is needed and no work can be done in ACPI to solve this, please follow the bug here:
*** Bug 60707 has been marked as a duplicate of this bug. ***