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intelfx
SCSI Port
Posts: 47
Registered: ‎09-15-2016
Location: RU
Views: 2,115
Message 111 of 120

Re: Linux status of Fibocom L850-Gl


@BigDong wrote:

if you look here then you will notice that "Bypass Lenovo Whitelist for T470/Carbon X1 G6 and other newer Lenovo laptops"

 


TBH I'm not sure who added this statement. When I wrote this walkthrough on the ArchWiki, I specifically stated it's been tested on X1C6 only.

 


@BigDong wrote:

What is X1Y3 ? is it X1 Gen 7?


Why won't you at least try to google both names for a bit? X1Y3 is X1 Yoga 3rd, X1C7 is X1 Carbon 7th.

BigDong
SCSI Port
Posts: 47
Registered: ‎10-15-2019
Location: FR
Views: 2,101
Message 112 of 120

Re: Linux status of Fibocom L850-Gl

That was what I thought but then... why do you speak about yoga? 

 

The statement is from the Github project. You can click on blame if you want to know who and when it was added. 

abrasive
Fanfold Paper
Posts: 6
Registered: ‎10-15-2019
Location: AU
Views: 2,087
Message 113 of 120

Re: Linux status of Fibocom L850-Gl

OK, I have my L850-GL happily running under ModemManager on Gentoo Linux now.

 

It turns out that someone in the chain implemented what they call "FCC Lock". This locks the modem in flight mode until ModemAuthenticator.exe unlocks it, using a key in the laptop's SMBIOS. This is clearly a regulatory compliance thing, along with the BIOS whitelist: because you have to test the software, radio, and antennas in the final product as a unit, it makes sure that people don't swap modems into the wrong machines, et cetera, and violate the regs.

 

Of course, they haven't implemented this for Linux because a) porting the PCI driver would be expensive, and b) doing the RF testing would be very expensive. (It may also be that dynamic power reduction to meet SAR limits is implemented in the Windows driver, though I have not seen it.)

 

Anyway, you can bypass the lock pretty trivially, subject to the caveat that you may well be breaking the law where you live, or you might cook your lap because no dynamic power reduction. Be wise, please.

 

https://github.com/abrasive/xmm7360

BigDong
SCSI Port
Posts: 47
Registered: ‎10-15-2019
Location: FR
Views: 2,081
Message 114 of 120

Re: Linux status of Fibocom L850-Gl

I am even more surprised, this person here says it is possible to use L850-GL with Debian, while here we mainly see people buying a Dell EM7455 to be able to use the 4G on their X1 carbon, any opinion about this?

intelfx
SCSI Port
Posts: 47
Registered: ‎09-15-2016
Location: RU
Views: 2,040
Message 115 of 120

Re: Linux status of Fibocom L850-Gl


@abrasive wrote:
Oof, what a thread! I just got a T490 so time for me to jump in too.

I've done a bit of reverse engineering and come up with a couple of things.
One, a way to flip the modem to USB mode from within Linux.
And two, some of a PCI driver (enough to send AT commands, not enough to run MBIM).

You can find at least the former here:

https://github.com/abrasive/xmm7360

On my T490 the device ends up stuck in flight mode (AT+CFUN? returns 4,0 and MBIM power on requests return Busy).
I don't know if this is the WAN disable line to the M.2 slot and it's actually in flight mode? - but that doesn't appeared to be set up on this laptop (the GPIO used by the SWAN ACPI method isn't even set as an output).
I wonder if it actually depends on the ModemAuthenticator service that runs on Windows and "unlocks" the modem?
But then I'd expect it to boot in my Windows VM when I pass through the modem device, and it doesn't even with the ModemAuthenticator running. I haven't done any digging to see if the "Authenticator" is actually talking to it though.
I'm stumped so far and would be interested to hear how other people get on.

Just noticed your post. This is gold! Now we just have to generalize it and call it a pci_modeswitch :-)

 

I thought it couldn't be done; does ACPI _RST actually toggle power supply?

abrasive
Fanfold Paper
Posts: 6
Registered: ‎10-15-2019
Location: AU
Views: 2,029
Message 116 of 120

Re: Linux status of Fibocom L850-Gl


@intelfx

I thought it couldn't be done; does ACPI _RST actually toggle power supply?

On my T490 it's wired to the card's main reset line, which is perfect. (There's a separate PCIe reset line which is not what we want.)

 

There's an issue on the GH repo about it not working on a P52 so it may not be universal. That said, there are ACPI power off and on methods too, so it should be workable.

 

I'm hoping to find an ACPI-free / pure PCI way to do it though, that would be more portable.

 

I've also been able to kick my card into permanent USB mode so it survives a power cycle! Unfortunately I then also learned it's not on the BIOS whitelist... it does look like the VID/PID should be changeable but I haven't figured it out yet. (If someone wants to loan me another modem and a USB adapter so I don't render my lappy unbootable again, that'd help ;-)

rfox
Fanfold Paper
Posts: 10
Registered: ‎10-30-2011
Location: DE
Views: 2,019
Message 117 of 120

Re: Linux status of Fibocom L850-Gl

Nice to see progress (finally) on this topic!  I purchased an X1G6 last year with this card and was quite disappointed about the Linux support (considering my previous Thinkpad X220 had no issues) - I falsely assumed Lenovo supports using Linux on their Thinkpad products as they have in the past . . .

 

I'm still confused about one thing - If this card works with Windows, and it's simply a regulatory topic (not technical limitation) - why is it necessary to re-certify the same device under another OS??  This seems obnoxious . . .

 

Also, Lenovo's response to the community has been less than upfront or professional (ignoring this topic for quite some time until enough customers fought back) - they should at least offer to exchange the card with a known supported model for those like us who need / want Linux on these products.

 

Thinkpad models especially were notorious for good Linux compatibility, and now I'll think twice before I refresh my laptop . . .

 

Cheers,

R.Fox

dbao
Punch Card
Posts: 110
Registered: ‎11-07-2009
Location: US
Views: 1,951
Message 118 of 120

Re: Linux status of Fibocom L850-Gl


@abrasive wrote:
 

https://github.com/abrasive/xmm7360


To run acpi_call, you need either disable secure boot from UEFI, or sign acpi_call kernel module.

BigDong
SCSI Port
Posts: 47
Registered: ‎10-15-2019
Location: FR
Views: 1,682
Message 119 of 120

Re: Linux status of Fibocom L850-Gl

This is the exact same thing as the abrasive repository except it will keep working after reboot: https://github.com/juhovh/xmm7360_usb

papaneuf
Paper Tape
Posts: 5
Registered: ‎12-05-2019
Location: US
Views: 1,280
Message 120 of 120

Re: Linux status of Fibocom L850-Gl

I never had a problem with Lenovo and Linux. This does not bode well for the future.

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