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intelfx
SCSI Port
Posts: 47
Registered: ‎09-15-2016
Location: RU
Views: 474
Message 81 of 120

Re: Linux status of Fibocom L850-Gl


@MarkRHPearson wrote:

 

As I found out this morning from the driver team (and your link to the overview also mentions) on our boards the device is connected to PCIe and not to USB, so fixing the USB blacklist is not the solution.


I have just verified this is NOT the case. The Fibocom L850-GL modem (serial number D1L3JH00Z9) that came with my Lenovo X1 Carbon 6th gen (serial number PF169UNM) is connected to BOTH USB and PCIe buses. I have verified this by connecting the modem to an external USB-only capable M.2 adapter. The modem in question appears as a fully functional USB device with VID 0x8087, PID 0x095a.

 

Additionally, the WWAN M.2 slot on the X1 Carbon 6th gen itself is also known to be connected to both USB and PCIe buses (which is indirectly confirmed by the fact that plugging in a USB-only modem triggers an "Unauthorized card" whitelist failure).

 

Please clarify what exactly do you mean by this statement. As far as the community is aware, the chipsets on these modems are connected to BOTH buses, but they appear to make a one-time choice which bus to speak upon power-up. It should be possible for Lenovo firmware engineers to add a BIOS-level option to disable or otherwise block the PCIe bus on this slot, thereby forcing the modem to select the USB bus.

dbao
Punch Card
Posts: 100
Registered: ‎11-07-2009
Location: US
Views: 461
Message 82 of 120

Re: Linux status of Fibocom L850-Gl


@MarkRHPearson wrote:

 

 As I found out this morning from the driver team (and your link to the overview also mentions) on our boards the device is connected to PCIe and not to USB, so fixing the USB blacklist is not the solution.

 


L850GL has both USB and PCIe pin out,  and can be able to connect to USB pins on M.2 interface. There are a lot of discussions at the begining of this thread.  The only reason " the device is connected to PCIe and not to USB" is that Lenovo blocks USB vid at BIOS.

 

If you look at Windows L850 driver carefully. It is still a Qualcomm USB driver. The difference is, this time it is connecting to L850's PCIe interface via a PCI-USB bridge driver. 

intelfx
SCSI Port
Posts: 47
Registered: ‎09-15-2016
Location: RU
Views: 448
Message 83 of 120

Re: Linux status of Fibocom L850-Gl


@dbao wrote:

 

The only reason " the device is connected to PCIe and not to USB" is that Lenovo blocks USB vid at BIOS.


Nope, not correct as well. See the above post. Lenovo's BIOS-level whitelists work post-factum: if an unauthorized device appears, the boot process is halted. Bus selection logic is in the modem chipset, it simply prioritizes PCIe whenever it's available.

 

For this to work, both bus selection logic and whitelisting logic need to be accounted for.

dbao
Punch Card
Posts: 100
Registered: ‎11-07-2009
Location: US
Views: 426
Message 84 of 120

Re: Linux status of Fibocom L850-Gl


@intelfx wrote:

@dbao wrote:

 

The only reason " the device is connected to PCIe and not to USB" is that Lenovo blocks USB vid at BIOS.


Nope, not correct as well. See the above post. Lenovo's BIOS-level whitelists work post-factum: if an unauthorized device appears, the boot process is halted. Bus selection logic is in the modem chipset, it simply prioritizes PCIe whenever it's available.

 

For this to work, both bus selection logic and whitelisting logic need to be accounted for.


Many people, including me (read the begining of this thread),  tried to disable PCIe physical pins to force enabling L850GL's USB interface, and USB vid immediately triggers BIOS whitelist.

 

 

intelfx
SCSI Port
Posts: 47
Registered: ‎09-15-2016
Location: RU
Views: 413
Message 85 of 120

Re: Linux status of Fibocom L850-Gl


@dbao wrote:

 

Many people, including me (read the begining of this thread),  tried to disable PCIe physical pins to force enabling L850GL's USB interface, and USB vid immediately triggers BIOS whitelist.


That's exactly what I wrote. There's just no causality. There's separately bus selection logic (that forces the chipset to select PCIe if it sees PCIe) and whitelisting logic (that only allows PCIe because reasons). Both need to be fixed separately.

dbao
Punch Card
Posts: 100
Registered: ‎11-07-2009
Location: US
Views: 412
Message 86 of 120

Re: Linux status of Fibocom L850-Gl


@intelfx wrote:

@MarkRHPearson wrote:

 

As I found out this morning from the driver team (and your link to the overview also mentions) on our boards the device is connected to PCIe and not to USB, so fixing the USB blacklist is not the solution.


I have just verified this is NOT the case. The Fibocom L850-GL modem (serial number D1L3JH00Z9) that came with my Lenovo X1 Carbon 6th gen (serial number PF169UNM) is connected to BOTH USB and PCIe buses. I have verified this by connecting the modem to an external USB-only capable M.2 adapter. The modem in question appears as a fully functional USB device with VID 0x8087, PID 0x095a.

 

Additionally, the WWAN M.2 slot on the X1 Carbon 6th gen itself is also known to be connected to both USB and PCIe buses (which is indirectly confirmed by the fact that plugging in a USB-only modem triggers an "Unauthorized card" whitelist failure).

 

Please clarify what exactly do you mean by this statement. As far as the community is aware, the chipsets on these modems are connected to BOTH buses, but they appear to make a one-time choice which bus to speak upon power-up. It should be possible for Lenovo firmware engineers to add a BIOS-level option to disable or otherwise block the PCIe bus on this slot, thereby forcing the modem to select the USB bus.


This is not news. We all know Lenovo blocks Linux inferface in purpose. The funny thing is now they told us they are working very hard,  doing original research to make this thing work.  They don't have to write a generic PCI wwan driver, just add USB vid to whitelist, 5 minutes!

 

 

dbao
Punch Card
Posts: 100
Registered: ‎11-07-2009
Location: US
Views: 409
Message 87 of 120

Re: Linux status of Fibocom L850-Gl


@intelfx wrote:

@dbao wrote:

 

Many people, including me (read the begining of this thread),  tried to disable PCIe physical pins to force enabling L850GL's USB interface, and USB vid immediately triggers BIOS whitelist.


That's exactly what I wrote. There's just no causality. There's separately bus selection logic (that forces the chipset to select PCIe if it sees PCIe) and whitelisting logic (that only allows PCIe because reasons). Both need to be fixed separately.


You can just cut off PICe pin out on L850 board.

Lenovo Employee MarkRHPearson
Lenovo Employee
Posts: 57
Registered: ‎07-22-2019
Location: CA
Views: 395
Message 88 of 120

Re: Linux status of Fibocom L850-Gl

First off my apologies - I thought the driver team was looking into this, but I didn't have all the details. I should have checked harder before my initial post. Still new to the team and still learning...

 

I got the following back from our driver team:
"Intel is not supporting PCIe configuration and they have no plan to do so.

Also, to support WWAN feature legally, we need to provide DPR(Dynamic Power Reduction) software. FCC regulates the energy that is absorbed by human body to a certain limit. This is called SAR requirement. To meet this regulation, we need to constantly check the orientation and proximity of the system and dynamically reduce radio output power if the location of the antenna(s) get too close to human body. To write DPR we need API to control RF output. Intel does not provide such API neither."

 

I think that explains the reasons why it's not available now - and why it's not obvious to enable it.

 

I'd be interested to get some feedback from folk who understand this better for opinions/corrections. Are there any open source tools/projects out there that can be used to move this item forward?

NikosAlexandris
SCSI Port
Posts: 77
Registered: ‎04-28-2014
Location: IT
Views: 386
Message 89 of 120

Re: Linux status of Fibocom L850-Gl

Dear @dbao, reading your posts, overall, it is evident that you are very knowledgeable and technically skilled.

All of your know-how, is exactly required and useful towards a constructive dialog with Lenovo.

 

However and with all the respect, one of your last posts, i.e.

 


@dbao

 This is not news. We all know Lenovo blocks Linux inferface in purpose. The funny thing is now they told us they are working very hard,  doing original research to make this thing work.  They don't have to write a generic PCI wwan driver, just add USB vid to whitelist, 5 minutes!

does not help in any way the current situation.

 

Each and every one interested on this, or any other, subject, tries to contribute positively in our public dialog.

Please, @all, let us consider this magic tripplet filter before speaking up publicly:

 

- Is it true (what I want to say or write)?

- Is it necessary (or, I would say, useful)?

- Is it kind?

 

 

Remote Sensing & Geomatics
GPG Key Fingerprint 6F9D4506F3CA28380974D31A9053534B693C4FB3
rushforth
Punch Card
Posts: 20
Registered: ‎06-22-2018
Location: US
Views: 353
Message 90 of 120

Re: Linux status of Fibocom L850-Gl

@MarkRHPearson

 

Thanks for your reply.

 

So.  If this works in Windows, then the hardware is approved by FCC and possible to work.  Is the driver team saying "Intel won't support PCIe configuration in Linux, so our hands are tied."  

 

Or possibly "Even if we fixed the USB/PCI whitelist & initialization to allow the card to use the pre-existing linux drivers, it would not meet FCC requirements, because in Linux DPR is not supported."

 

Trying to understand which issue it is, and why other laptops with tihs card work in Linux and seeminly are legal.

 

Thanks!

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