Bug 215021

Summary: Single core AMD Turion ML-37 laptop does not respond until keys are pressed
Product: Base System Reporter: Jack <xxjack12xx>
Component: kernAssignee: freebsd-bugs (Nobody) <bugs>
Status: New ---    
Severity: Affects Only Me CC: ish, xxjack12xx
Priority: ---    
Version: 11.0-STABLE   
Hardware: amd64   
OS: Any   

Description Jack 2016-12-03 02:56:05 UTC
I have a single core AMD Turion ML-37 laptop running 11.0-RELEASE,11.0-STABLE,12.0-CURRENT that does not respond unless keys are pressed.

The system will boot and mount disks but hangs after that. When a key is pressed, it will boot further and further until it reaches the login prompt. If no keys are pressed before the login prompt, the system will hang until a key is pressed.

When shutting down the system, nothing will happen when issued a halt -p until keys are pressed. When pressing keys, it will move further along the shutdown process but hang if no keys are pressed.

Both these behaviors happen on a stock install and even occurs during the installer process from cd. The installer dialog boxes will not move unless keys are pressed after each action.

I've also noticed that the system will move if you ping it instead of pressing keys, but that only works if the laptop has an ip assigned to it.
Comment 1 Masachika ISHIZUKA 2018-02-18 10:48:17 UTC
My machine is duron applebred 1.6GHz (single core i386 socket A) and I have the same issue.
Both of 11.0-RELEASE (i386) and 11.1-RELEASE (i386) have the same problem. 10.4-RELEASE (i386) dose not have this problem.
With 11.x-RELEASE, remote access of ssh will be stopped sometimes and if it happened, internal clock is also stopped until any keys of local keyboard are pressed.
Celeron 1400MHz (single core i386 socket 370) dose not have this issue with 11.x-RELEASE.
Before some days, Celeron machine's power unit was failed and I move this hdd to duron machine and found this issue.
Comment 2 Jack 2018-02-18 10:51:28 UTC
I can also confirm this only happens starting at 11.0, 10.4 appears to work fine. Maybe something to do with single core amd? My dual core amds don't experience this issue.
Comment 3 Jack 2018-05-23 19:57:14 UTC
Anyone have any idea what changed between 10 and 11 that's causing this? Seems like 11+ can't get enough entropy to function or something.
Comment 4 Jack 2018-08-21 22:59:32 UTC
Some additional details:

If I cat /dev/random > /dev/null, the system functions normally but the moment cat is stopped (system poweroff via poweroff command), the system will hang until keys are pressed up until it says "All buffers synced". Then the system hangs forever and never powers off.
Comment 5 Jack 2019-01-08 21:21:22 UTC
Running FreeBSD 12 release appears to not have any such issues with hanging until keys are pressed.
Comment 6 Masachika ISHIZUKA 2019-11-05 13:34:36 UTC
Sorry for too late reply.
Thank you for good information of 'cat /dev/random > /dev/null', that is very useful and I could do successfully 'freebsd-update -r 12.1-RELEASE upgrade' with it on a single core duron 11.1-RELEASE machine.
Although 12.1-RELEASE has the issue with hanging until keys are pressed on my single core duron machine, that less often than 11.x-RELEASE.
Comment 7 Jack 2019-11-06 06:18:51 UTC
It still seems to hang like 11 if I am running the laptop on battery but doesn't hang if it's plugged into the wall. Very strange.
Comment 8 Andriy Gapon freebsd_committer 2019-11-06 09:24:49 UTC
It might that on battery it uses deeper C states and there is some problem with interrupt delivery in those states.
You can compare hw.acpi.cpu.cx_lowest and dev.cpu.0 sysctls in both modes to see if that's the case.