Bisected 3.12.0-rc1 Laptop screen goes blank during kernelboot

During boot time my laptop screen goes blank when de kernel switches the screen to another resolution. The backlight is on. Eventually a kde login box appears out of the blackness. Swiching to a lower resolution gives me a black screen again. After testing the [email protected] developers test-tree problem less they sugested a bisect. That bisect ended in:

commit 137b944e100278d696826cf25c83014ac17473fe

Author: Daniel Lezcano <[email protected]>
Date:   Wed Jun 12 15:08:48 2013 +0200

cpuidle: Make it clear that governors cannot be modules

cpufreq governors are defined as modules in the code, but the Kconfig options do not allow them to be built as modules. This is not really a problem, but the cpuidle init ordering is: the cpuidle init functions (framework and driver) and then the governors. That leads to some weirdness in the cpuidle framework.

Namely, cpuidle_register_device() calls cpuidle_enable_device() which fails at the first attempt, because governors have not been registered yet. When a governor is registered, the framework calls cpuidle_enable_device() again which runs __cpuidle_register_device() only then. Of course, for that to work, the cpuidle_enable_device() return value has to be ignored by cpuidle_register_device().

Instead of having this cyclic call graph and relying on a positive side effects of the hackish back and forth cpuidle_enable_device() calls it is better to fix the cpuidle init ordering.

To that end, replace the module init code with postcore_initcall() so we have:

* cpuidle framework : core_initcall
* cpuidle governors : postcore_initcall
* cpuidle drivers : device_initcall

and remove the corresponding module exit code as it is dead anyway (governors can't be built as modules).

[rjw: Changelog]

Signed-off-by Daniel Lezcano <[email protected]>

Signed-off-by Rafael J. Wysocki <[email protected]>

:040000 040000 45e7cb28411864c00b62296a7ff239f9f139d5d9
86a36b01dee52a77cfbab41a973b7a2bfa44ce34 M drivers

Reverting it makes the problem go away.

Add linux-pm.

-Aaron

Quoted 51 lines · Hans de Bruin

During boot time my laptop screen goes blank when de kernel switches the screen to another resolution. The backlight is on. Eventually a kde login box appears out of the blackness. Swiching to a lower resolution gives me a black screen again. After testing the [email protected] developers test-tree problem less they sugested a bisect. That bisect ended in:

commit 137b944e100278d696826cf25c83014ac17473fe

Author: Daniel Lezcano <[email protected]>
Date:   Wed Jun 12 15:08:48 2013 +0200

cpuidle: Make it clear that governors cannot be modules

cpufreq governors are defined as modules in the code, but the Kconfig options do not allow them to be built as modules. This is not really a problem, but the cpuidle init ordering is: the cpuidle init functions (framework and driver) and then the governors. That leads to some weirdness in the cpuidle framework.

Namely, cpuidle_register_device() calls cpuidle_enable_device() which fails at the first attempt, because governors have not been registered yet. When a governor is registered, the framework calls cpuidle_enable_device() again which runs __cpuidle_register_device() only then. Of course, for that to work, the cpuidle_enable_device() return value has to be ignored by cpuidle_register_device().

Instead of having this cyclic call graph and relying on a positive side effects of the hackish back and forth cpuidle_enable_device() calls it is better to fix the cpuidle init ordering.

To that end, replace the module init code with postcore_initcall() so we have:

* cpuidle framework : core_initcall
* cpuidle governors : postcore_initcall
* cpuidle drivers : device_initcall

and remove the corresponding module exit code as it is dead anyway (governors can't be built as modules).

[rjw: Changelog]

Signed-off-by Daniel Lezcano <[email protected]>

Signed-off-by Rafael J. Wysocki <[email protected]>

:040000 040000 45e7cb28411864c00b62296a7ff239f9f139d5d9
86a36b01dee52a77cfbab41a973b7a2bfa44ce34 M drivers

Reverting it makes the problem go away.

todays kernel with problem:

#
# CPU Idle
#
CONFIG_CPU_IDLE=y
# CONFIG_CPU_IDLE_MULTIPLE_DRIVERS is not set
CONFIG_CPU_IDLE_GOV_LADDER=y
CONFIG_CPU_IDLE_GOV_MENU=y
# CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED is not set
CONFIG_INTEL_IDLE=y

==> /sys/devices/system/cpu/cpuidle/current_driver <== acpi_idle

==> /sys/devices/system/cpu/cpuidle/current_governor_ro <== menu

[    0.056000] cpuidle: using governor ladder
[    0.056000] cpuidle: using governor menu

3.8.0:
bash-4.1# tail /sys/devices/system/cpu/cpuidle/* ==> /sys/devices/system/cpu/cpuidle/current_driver <== acpi_idle

==> /sys/devices/system/cpu/cpuidle/current_governor_ro <== menu

[    1.759857] cpuidle: using governor ladder
[    1.763849] scsi 0:0:0:0: Direct-Access     ATA      TOSHIBA MK4009GA
BS11 PQ: 0 ANSI: 5
[    1.767098] cpuidle: using governor menu