On Tue, 26 Sep 2017 09:53:23 +0300 Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> wrote: > > Do you have any more details, logs or documentation about these 10Gbps ASM1142 bugs in xHCI driver? > I'd be interested in getting that fixed > > Thanks > Mathias I know exactly what must be changed in the XHCI driver, but I did not have time to implement it. If I will succeed soon to have a weekend in which I will not be busy, I could submit a complete patch. I can test the support for 10 Gb/s on 6 different kinds of motherboards, 2 with ASM 1142 and 4 with the USB 3.1 controllers from Intel Thunderbolt 3, and also with 3 or 4 different kinds of USB 10 GB/s to SATA 6 Gb/s bridges. The problem in the current XHCI driver was created by a patch from 2 years ago, which added SuperSpeedPlus detection. However, the method used is wrong, according to both the Intel XHCI specification and the ASMedia datasheets. The only explanation for the origin of the wrong detection method that I can imagine is that probably this method was correct for some of the first ASMedia USB 3.1 controllers, maybe for ASM 1042. I suppose that the first ASMedia XHCI controllers did not implement correctly the XHCI specification, but later they were corrected, at least starting with ASM 1142. Of course, the Intel USB 3.1 controllers must have implemented the Intel specification since the beginning. So the status is that the current Linux XHCI driver cannot detect the SuperSpeedPlus support in any not very old motherboard, i.e. any motherboard with ASM 1142 or newer, or any motherboard with Intel Thunderbolt 3. (The current XHCI driver tries to read a "3.1" value from a register that according to all specifications and datasheets and also according to my experiments can have only the "3.0" value, even in USB 3.1 controllers. The correct SuperSpeedPlus detection involves other registers and it is more complex.) In have already implemented the part that detects the capabilities of the XHCI controller but there are also some changes that must be done to detect correctly the capabilities of a SuperSpeedPlus device after it is connected to a USB 3.1 port, otherwise the 10 Gb/s link is not established. Best regards ! -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
