Comment 64 for bug 1749961

I did a little bit of research on the Razer Core Chroma usb card.

This card uses 3 ASM1142 pcie to usb bridges (let's call them IC_0, IC_1, IC_2) and the PCIe 4x connector is wired in a non-standard way.

IC_0 is wired up to the PCIe in a normal fashion using only the pcie lane 0 (TX and RX) and the "usual" clock lane.

IC_1 data lanes are wired to pci lane 1 (TX and RX) but the clock lane has been wired to lane 3 RX.

IC_2 data lanes are wired to pci lane 2 (TX and RX) but the clock lane has been wired to lane 3 TX.

Furthermore IC_2 has one of it's two USB interfaces wired to an USB to Ethernet bridge (ASIX AX88179), while the other one is connected to another micro-controller on the Chroma's main board that I presume controls the LED colours, in windows this IC is detected as some sort of mouse so I would say that Razer have recycled some code to implement this...

All clock lanes merge together in another IC (IC_4) that is on the Chroma's main board.

I would say that they are doing some sort of Time-division to share the same PCIe port for three different devices and this is provoking all the mess. I have read people having trouble in every single OS (MacOS, Windows and Linux) with this device. I would expeted such junkie desing on low budged development, but never in a company as Razer..... And their response to they issue is been horrendous... something to bare in mind in future acquisitions....

Anyway it would be interesting to know if other people having trouble has more of one ASM1142 or not....