Category: hardware

Moto G6 Plus without GPS Lock

I’ve been a quite happy owner of the Moto G6 Plus for some years now. Since the beginning, I always had a “minor” issue: sometimes the GPS started to suddenly stopped getting a lock. Which was especially cumbersome, if I was using the phone as navigation system while driving. Today, the GPS lost it’s locking mid-drive and I’ve not been able to reestablish it, not even by power-cycling the device. Also various attempts of changing battery saving options and changing location accuracy settings did not result in any improvements (normally it did). The internal diagnostics of the device (*#*#2486#*#*) just said it didn’t get a lock.

My assumption was that it somehow might be related to the A-GPS data. Therefore I looked if there was any tool in the Play Store that might help me clear the A-GPS data, and luckily I stumbled upon “GPS Status & Toolbox“. Even in the free version it allowed to clear the A-GPS data and from this “cold start” mode the device got a lock rather quickly. To support the devs, I decided to upgrade to the PRO version for less than €2,00.

I’m now curious if this is a long-term fix or if it was just lucky coincidence. I’m hoping for the first.

Quick Checklist

  • Disable battery optimizations on Google Maps (and any navigational map you might be using)
  • Disable battery optimization for the “LocationService”
  • Turn off WiFi- and Bluetooth-Background Scans since they might clash with Improved Google Location Accuracy setting
  • Use a tool (like GPS Status & Toolbox) to reset A-GPS data of the GPS receiver

Update 2020-01-06

Since I’ve installed “GPS Status & Toolbox“, the problem has been fixed. Never had the problem of not getting a GPS fix any more.

Linux, Western Digital Green & Load Cycle Count

Today when looking at my Munin graphs for S.M.A.R.T. values of my always-on PVR box, I noticed that within a year, my Western Digital Green-line disks had degraded their Load_Cycle_Count attribute to a shocking low level of below 20 (in S.M.A.R.T., low levels are bad). The raw value indicated that the three of the four disks had parked their heads more than a half million times, each:

#$ for D in sda sdb sdc sdd; do sudo smartctl -A /dev/$D | grep "^193"; done
193 Load_Cycle_Count 0x0032 014 014 000 Old_age Always - 559966
193 Load_Cycle_Count 0x0032 200 200 000 Old_age Always - 111
193 Load_Cycle_Count 0x0032 010 010 000 Old_age Always - 572713
193 Load_Cycle_Count 0x0032 013 013 000 Old_age Always - 563615

Munin’s year graph for one of the disks showed shocking truth, the disk was aging fast:

/dev/sdd over the last year

When watching the above shell script with watch over time, I noticed, that some of the disks parked their heads about 2-3 times per minute. As the machine is always on, this sums up pretty quickly.

Research soon got me to several blog posts and forum discussions of the issues. Western Digital itself recommends using hdparm to disable advanced power management of the disk. This seems to be unsupported, by my drives, though.
Another way provided by WD, which has been often recommended, was downloading a DOS tool from Western Digital to set the idle timer of the disks. Not really the way I wanted to go.

Fortunately, I also found a blog entry that directed me to the idle3 project, that provides a way to set it from Linux.

The tool was very easy to compile (just one call to make), and then provided me with the current settings:

#$ for D in sda sdb sdc sdd; do sudo ./idle3ctl -g /dev/$D; done
Idle3 timer set to 80 (0x50)
Idle3 timer set to 80 (0x50)
Idle3 timer set to 80 (0x50)
Idle3 timer set to 80 (0x50)

Disabling the timer was easy enough for all four drives:

#$ for D in sda sdb sdc sdd; do sudo ./idle3ctl -d /dev/$D; done
Idle3 timer disabled
Please power cycle your drive off and on for the new setting to be taken into account. A reboot will not be enough!
Idle3 timer disabled
Please power cycle your drive off and on for the new setting to be taken into account. A reboot will not be enough!
Idle3 timer disabled
Please power cycle your drive off and on for the new setting to be taken into account. A reboot will not be enough!
Idle3 timer disabled
Please power cycle your drive off and on for the new setting to be taken into account. A reboot will not be enough!

The warning should be taken seriously though, the command took only effect after powering the whole system down, even though the drive itself reported idle timer to be disabled right away.

Update 2019-07-13: As I needed to adjust the IDLE mode of one of my Western Digital Red (WD30EFRX-68EUZN0) drives, I found out that more recent versions of hdparm support getting/setting the mode, even via certain USB adapters. This was a huge improvement for me, since the tool mentioned above requires the drive directly attached to a SATA port, which always required shutting down the PC and re-wiring the disks for changing the settings. The relevant command is as follows (replace it with your appropriate device). And yes, you need the scary parameter.

hdparm -J 0 --please-destroy-my-drive /dev/sde

It is still necessary to power down the device before the setting takes effect.

OCZ Vertex2, Linux, and ancient nForce 430 chipset

Today I finally received my brand-new Ocz Vertex2 OCZSSD2-2VTXE120G 120GB and eagerly wanted to install it in my 4-year-old HP workstation which currently is running Ubuntu 10.10 exclusively.

After setting up the alignment according to some tutorials I found online, I started the setup process. Shortly after starting the copy step of the installation, the whole process came to a grinding halt with filesystem errors. Looking into the kernel debug messages it seemed like SATA commands were causing errors. After checking hardware, cables and switching SATA ports, I began researching the issue and soon found that the issue might be fixed in the next firmware version of the drive. So I wanted to upgrade from 1.23 to 1.24, which could only be done in Windows…

After installing a trial of Windows 7, I finally wanted to upgrade the firmware, but the drive was not detected, but was accessible. The release notes indicated that I would need to switch to AHCI mode. After several attempts, includig a BIOS update, I realized that there was no way to do this with my old hardware, as my nForce 430 chipset simply doesn’t support it.

So my only remaining option was to simply try the kernel arguments I read to be the fix for 1.24 with the 1.23 hardware.

So, if you add the following kernel option during installation and afterwards for every boot, the disk seems to work quite well (source):

libata.force=norst

Actually, this forces the ATA driver in Linux to not issue any reset commands on the bus. I really don’t understand why this improves/fixes the problem, but it seems the device has issues when being reset on my chipset. I can also notice this that in 2 out of 3 attempts if I reboot the PC the disk is not recognized any more before I reboot again.

Despite these issues, the SSD now runs with astonishing performance with the suggested 32 head / 32 sector alignment, and a 512kB partition alignment scheme. After an initial TRIM with hdparm‘s wiper.sh I enabled -o discard for my ext4 partition and could also verify using hdparm that this results in the sectors being trimmed. Please note, that you need to manually compile and install the latest hdparm version on Ubuntu 10.10, as the included version fails with the very long free block list and doesn’t handle splitting the sectors in multiple requests. The latest version doesn’t have this issue any more.

Novatel Merlin U740 using only Windows 7 onboard tools

I have lost the install CD of my Novatel Merlin U740, an older PCMCIA UMTS card. As a consequence I got no “Mobilink Connection Manager” after installing Windows 7 on my notebook. Fortunately I found this guide by Novatel Wireless which explains how to connect using only on-board tools in Windows Vista, by setting up a dial-up connection. It still works in Windows 7. The important part is to set the APN as part of the driver’s initialization string.

The telephone number you have to set is *99#, which should be provider-independent.

The following settings are for yesss.at only:
Username: web
Passwort: web

Remember to set the APN as part of the driver’s connection string in Window’s “Device Manager” as described in the PDF.

Again, for yesss.at this is: AT+CGDCONT=1,"IP","web.yesss.at"

For this to work properly, the SIM must not have a PIN set, as otherwise the SIM will be locked and the dialer cannot dial out. For me this is ok, as it is a pre-paid card which can hardly be abused if it gets stolen, but your situation might be different, so please consider the security implications. (I suspect that it should be possible to unlock the SIM card somehow using the AT+CPIN=1234 command, but I did not research how to separate several initialization strings, as it did not work immediately.)

The solution works quite well for me, even under Windows 7. Disadvantage is that there is no way to tell the signal strength and exact mode of operation (despite the color-coded status led on the Merlin U740).

Waiting for WLAN and UMTS for OpenMoko

I am currently thinking a lot about the OpenMoko project. Unfortunately OpenMoko at the moment provides hardware which is limited to GPRS, Bluetooth, and/or USB 1.0 for connectivity. In autumn there should be the next generation which should include a WLAN (and maybe even UMTS?) support. It will be called Neo 1973 – GTA02.

Together with Austrian-based one “H.U.I. Starter” rate (250MB @ UMTS, reduction to 56kBit/s above, 10€/month) this would be a nice package. However, if I could have UMTS, well, that would be better. Personally, WLAN is even more important for me, I could use it in the office or in my home, where I have WLAN access available and fall back to GPRS while being “on the road”.

For me this means: standby for autumn, because I can’t afford to invest US-$300 now and another US-$450 in a couple of month. Still, I am really, really interested in OpenMoko (and normally I wouldn’t invest that amount of money into a hobby of mine). Which means, I am standing by and waiting for news from the OpenMoko community…

In the meantime, if you understand German, you could listen to this very interesting Chaosradio Express Podcast.

On YouTube there are some very interesting videos about the Neo 1973.

OpenMoko – the Open Mobile Phone

This is cool! If you want to have a mobile phone based on Linux and pure OpenSource software, OpenMoko might be the right thing for you! I’m not so much in mobile development, but I find this almost more appealing than the iPhone, which at the moment is a very closed platform. If I find some time for a hobby like this, this US-$ 300 would be a nice investment. I hope this becomes a success to reward the company and the idea to explictly invite hackers/developers (both software & hardware) to improve a phone. A nice contrast to the usual anti-reverse-engineering and “hacking” philosophy most companies go along with.

Edit 2007-07-18: I accidentially misspelled OpenMoko as OpenMonko in the inital release, both in the title and in the text. I corrected this and the URL of the article to reflect the real name of the project: OpenMoko.