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Vovano

Member

Registered: 2015-06-05

Posts: 3

Dell n5110. Unrecognized AC adapter CPU throttling issue.

Hi!

I am trying to bypass not recognized AC adapter issue. This is not connection problem, looks like one of chips is damaged.

BIOS version A11.

My CPU

cat /proc/cpuinfo | grep 'model name' | uniq
model name	: Intel(R) Core(TM) i5-2430M CPU @ 2.40GHz

With pstate driver "performance" governor always decide to keep lower frequency.

cpupower output with acpi-cpufreq driver

cpupower frequency-info
analyzing CPU 0:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 10.0 us.
  hardware limits: 800 MHz - 2.40 GHz
  available frequency steps: 2.40 GHz, 2.40 GHz, 2.00 GHz, 1.80 GHz, 1.60 GHz, 1.40 GHz, 1.20 GHz, 1000 MHz, 800 MHz
  available cpufreq governors: ondemand, performance
  current policy: frequency should be within 800 MHz and 2.40 GHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency is 2.40 GHz.
  boost state support:
    Supported: yes
    Active: yes
    25500 MHz max turbo 4 active cores
    25500 MHz max turbo 3 active cores
    25500 MHz max turbo 2 active cores
    25500 MHz max turbo 1 active cores

cpupower monitor output

 sudo cpupower monitor
[sudo] password for vovano: 
    |Nehalem                    || SandyBridge        || Mperf              || Idle_Stats                              
CPU | C3   | C6   | PC3  | PC6  || C7   | PC2  | PC7  || C0   | Cx   | Freq || POLL | C1-S | C1E- | C3-S | C6-S | C7-S 
   0|  0.21|  0.00|  0.14|  9.91|| 91.19|  5.04| 73.18||  3.67| 96.33|   797||  0.00|  1.40|  0.43|  0.23|  0.00| 94.35
   2|  0.21|  0.00|  0.14|  9.91|| 91.19|  5.04| 73.18||  1.15| 98.85|   797||  0.00|  0.00|  1.67|  0.00|  0.00| 97.19
   1|  0.00|  0.00|  0.14|  9.91|| 96.13|  5.04| 73.18||  2.81| 97.19|   797||  0.00|  0.00|  0.06|  0.00|  0.00| 97.18
   3|  0.00|  0.00|  0.14|  9.91|| 96.13|  5.04| 73.18||  0.24| 99.76|   798||  0.00|  0.00|  0.00|  0.00|  0.00| 99.77

i7z

Cpu speed from cpuinfo 2394.00Mhz
cpuinfo might be wrong if cpufreq is enabled. To guess correctly try estimating via tsc
Linux's inbuilt cpu_khz code emulated now
True Frequency (without accounting Turbo) 2394 MHz
  CPU Multiplier 24x || Bus clock frequency (BCLK) 99.75 MHz

Socket [0] - [physical cores=2, logical cores=4, max online cores ever=2]
  TURBO ENABLED on 2 Cores, Hyper Threading ON
  Max Frequency without considering Turbo 2493.75 MHz (99.75 x [25])
  Max TURBO Multiplier (if Enabled) with 1/2/3/4 Cores is  30x/28x/28x/28x
  Real Current Frequency 798.12 MHz [99.75 x 8.00] (Max of below)
        Core [core-id]  :Actual Freq (Mult.)      C0%   Halt(C1)%  C3 %   C6 %  Temp      VCore
        Core 1 [0]:       797.81 (8.00x)        6.88    96.7       1       0    49      0.8055
        Core 2 [1]:       798.12 (8.00x)        4.57    98.5       0       0    49      0.8005





C0 = Processor running without halting
C1 = Processor running with halts (States >C0 are power saver modes with cores idling)
C3 = Cores running with PLL turned off and core cache turned off
C6, C7 = Everything in C3 + core state saved to last level cache, C7 is deeper than C6
  Above values in table are in percentage over the last 1 sec
[core-id] refers to core-id number in /proc/cpuinfo
'Garbage Values' message printed when garbage values are read
  Ctrl+C to exit

So real frequency is 800MHz, not 2.4GHz as governor says. Performance of laptop is according to it.
With "userspace" governor and -f 2.4GHz same problem. It is not in available cpufreq governors because of reinstalling.

BIOS limit is ok.

cat /sys/devices/system/cpu/cpu0/cpufreq/bios_limit
2401000

cat /sys/module/processor/parameters/ignore_ppc
1

MSR multiplier is 8. Always.

sudo rdmsr  0x198 -a --decimal --bitfield 15:8
8
8
8
8

My write to msr 0x199 has no effect, coz it constantly overwritten.
Even with uninstalled cpu frequency utils.

Does anyone have any idea why this is happening??

Last edited by Vovano (2015-06-05 15:11:01)

nagaseiori

Member

Registered: 2012-09-22

Posts: 72

Re: Dell n5110. Unrecognized AC adapter CPU throttling issue.

I have the Dell N4110, the 14 inch model. I sometimes get that error in the BIOS if I remove the AC adapter, turn off the computer, plug in the AC adapter, and turn on the computer again. I have to turn on the computer without the AC adapter and then plug it in later after POST.

Vovano

Member

Registered: 2015-06-05

Posts: 3

Re: Dell n5110. Unrecognized AC adapter CPU throttling issue.

I have the Dell N4110, the 14 inch model. I sometimes get that error in the BIOS if I remove the AC adapter, turn off the computer, plug in the AC adapter, and turn on the computer again. I have to turn on the computer without the AC adapter and then plug it in later after POST.

DATA pin of AC adapter was shorted with 19V. Recognition circuit is dead, I checked with an oscilloscope.

Vovano

Member

Registered: 2015-06-05

Posts: 3

Re: Dell n5110. Unrecognized AC adapter CPU throttling issue.

Sorry for necrobump.

So I didn't find any software way to solve this problem. I am solder attiny13 uC on motherboard and emulate behavior of undamaged AC adapter with help of code from this topic http://www.mikrocontroller.net/topic/186476 .