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Faster LAN via RasPi 3B+ LAN chip?

Posted: Thu Mar 15, 2018 11:30 am
by JesperBKK
I read today that there is a new Raspberry Pi 3B+ coming out, and that it has a 3 to 5 times faster LAN interface, due to a new LAN interface chip. Is it possible to:

1) Get the schematic for the Raspberry 3B+ (at least the LAN interface).

2) Use the new LAN chip with the Computer module?


Cheers


Jesper

Re: Faster LAN via RasPi 3B+ LAN chip?

Posted: Thu Mar 15, 2018 11:44 am
by JesperBKK
I've just found out that the new 3B+ uses the Microchip LAN7515 chip. It is also connected via USB to the Raspberry Pi CPU/SoC chip. So, the schematic is not really required.

My question then is:

Will it work (is there software drivers available) if I change my PCB to use the Microchip LAN7515 chip instead of the existing LAN chip?


Jesper

Re: Faster LAN via RasPi 3B+ LAN chip?

Posted: Thu Mar 15, 2018 11:48 am
by gsh
Yes, the latest kernel has support, otherwise it wouldn't work in Raspbian

Re: Faster LAN via RasPi 3B+ LAN chip?

Posted: Thu Mar 15, 2018 6:31 pm
by JesperBKK
Thank you so much for the quick answer.

I think I still have time to modify my PCB layout before going to production.


Jesper

Re: Faster LAN via RasPi 3B+ LAN chip?

Posted: Thu Mar 22, 2018 4:12 am
by plugwash
Though for some reason microchip seem to be hiding the details of the 7515 from their website, I dunno how hard it is to extract said details from a micochip sales office. :(

Re: Faster LAN via RasPi 3B+ LAN chip?

Posted: Thu Mar 22, 2018 9:50 am
by jamesh
plugwash wrote:
Thu Mar 22, 2018 4:12 am
Though for some reason microchip seem to be hiding the details of the 7515 from their website, I dunno how hard it is to extract said details from a micochip sales office. :(
It's a very new chip. Sales offices might no even be aware of it yet!

Re: Faster LAN via RasPi 3B+ LAN chip?

Posted: Sat Mar 24, 2018 10:45 am
by plugwash
I contacted them on twitter asking why the chip was missing from their website and got told to contact a sales office if I wanted more information on the chip. I wasn't sufficiently interested to follow up further.

https://twitter.com/plugwash/status/973941756940218369

Part of me wonders if the chip was designed at Raspberry Pi's request.

Re: Faster LAN via RasPi 3B+ LAN chip?

Posted: Sat Mar 24, 2018 10:56 am
by fruitoftheloom
plugwash wrote:
Sat Mar 24, 2018 10:45 am
I contacted them on twitter asking why the chip was missing from their website and got told to contact a sales office if I wanted more information on the chip. I wasn't sufficiently interested to follow up further.

https://twitter.com/plugwash/status/973941756940218369

Part of me wonders if the chip was designed at Raspberry Pi's request.

In this post it states the driver is for 7800

viewtopic.php?t=208399

Therefore your assumption would appear correct, and why not as PoE is also offered.

Re: Faster LAN via RasPi 3B+ LAN chip?

Posted: Sat Mar 24, 2018 12:16 pm
by jamesh
plugwash wrote:
Sat Mar 24, 2018 10:45 am
I contacted them on twitter asking why the chip was missing from their website and got told to contact a sales office if I wanted more information on the chip. I wasn't sufficiently interested to follow up further.

https://twitter.com/plugwash/status/973941756940218369

Part of me wonders if the chip was designed at Raspberry Pi's request.
Not sure. We do sell enough kit that suppliers will do that sort of thing now.

Re: Faster LAN via RasPi 3B+ LAN chip?

Posted: Sat Mar 24, 2018 12:56 pm
by hippy
jamesh wrote:
Thu Mar 22, 2018 9:50 am
It's a very new chip. Sales offices might no even be aware of it yet!
Microchip's own data suggests they updated their documentation to include the LAN7515 in June 2017 but there is no sign of the LAN7515 in any of their documentation or elsewhere beyond that one page comparison where the link to its datasheet leads to a generic home page.

It's all very odd, almost as if they know they have to admit to its existence but have no intention of making it easily available to the wider public. That's not uncommon, like Broadcom wasn't interested in providing its SoC's unless one would buy a huge quantity or could strike an 'inside deal', but it does seems a bit unusual for Microchip.

Some have suggested it is a chip supplied only to one manufacturer, and things are how they are to get around any anti-trust issues that could cause. I haven't seen evidence of that and other conspiracy theories are available.

Re: Faster LAN via RasPi 3B+ LAN chip?

Posted: Sun Mar 25, 2018 12:43 pm
by adun
The only information about the LAN7515 chip I could find was the microchip product compare page for LAN7515/LAN9514
https://www.microchip.com/wwwproducts/P ... 15/LAN9514

Additionally, the given specs about the LAN7515 chip are a bit confusing. In the description they mention:
USB 2.0 to 10/100/1000 Ethernet Bridge with 4-port USB 2.0 Hub

but further below the amount of "Downstream USB Ports" is set to 6 ?

Re: Faster LAN via RasPi 3B+ LAN chip?

Posted: Wed Apr 04, 2018 9:29 am
by mikerr
The specs are confused because its actually 2 cascaded usb hubs;

a 4port hub and a 3port hub attached (giving 6 ports) with the ethernet using one of those USB

The 3b+ spills the beans:

Code: Select all

lsusb -t
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=dwc_otg/1p, 480M
    |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M
        |__ Port 1: Dev 3, If 0, Class=Hub, Driver=hub/3p, 480M
            |__ Port 1: Dev 4, If 0, Class=Vendor Specific Class, Driver=lan78xx, 480M