Linux 3.16 Will Detect If Your Dell Latitude Is Falling

[phoronix]

Phoronix: Linux 3.16 Will Detect If Your Dell Latitude Is Falling

Matthew Garrett sent in the x86 platform driver updates on Tuesday that are going into the Linux 3.16 kernel. This pull request is interesting for Dell Latitude laptop owners...

http://www.phoronix.com/vr.php?view=MTcxNzg

[stiiixy]

These freefall sensors, are they seperate chips, or part of the GPS compassy integrated unit (I forget the name of that compass the planes used) like in phones or what?

[pali]

The sensors are basically accelerometers and can also be re-tasked for other non-standard purposes too with its open-source stack.

Michael, sensors are really ST acceleromenters, but on Dell laptops, it is not possible to use them for other purposes. It is because ACPI export only one IRQ which detect hdd freefall. Accelerometer is 3 axes but there is no way (on MS Windows too!) to read status of axes. So for anything else as hdd freefall is driver useless.

Also driver does not automatically park disk heads. For this action you need userspace daemon which will handle it. One for HP laptops (compabile) is in linux tree: Documentation/laptops/hpfall.c

These freefall sensors, are they seperate chips, or part of the GPS compassy integrated unit (I forget the name of that compass the planes used) like in phones or what?

It is separate ST Microelectronics accelerometer chip found in (probably) on motherboard. It can be found on laptop without GPS too.

To check if you have one, you can run this command:

$ find /sys/devices/ -name "*SMO*"

I think that every Latitude model has it.

[lethal]

Does it display a popup or such saying the laptop is falling ?

[pali]

When freefall irq occure driver report info to dmesg and process which reading /dev/freefall will be notified. Its up to you what will your userspace application with fall event do...

[emblemparade]

Love the photo.

In situations like that, you don't really need a driver to tell you that your laptop is failing.

[caligula]

Just makes me wonder, people now have SSD disks. What's the point? For SSD it's enough to sync data during the fall and poweroff?

[pali]

@caligula: And some people (like me) have 2 disks in laptop (combination of SSD for system and classic HDD for data). And just to note that Dell now has preconfigured Latitude models with hybrid SSD disks...

[caligula]

@caligula: And some people (like me) have 2 disks in laptop (combination of SSD for system and classic HDD for data). And just to note that Dell now has preconfigured Latitude models with hybrid SSD disks...

Ok then. I thought people just buy 1024 GB full SSD if they need the space.

[TheBlackCat]

Ok then. I thought people just buy 1024 GB full SSD if they need the space.

Not everyone has $500 to blow on a hard drive, especially not when you can get a regular laptop hard drive of the same size for a little over 1/10th the price.