On Thu, 12 Nov 2015, Felipe Balbi wrote: > Hi, > > Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> writes: > > On Thu, 12 Nov 2015, Felipe Balbi wrote: > > > >> >> >> Also, my problem seems to be sensitive to the host port being USB > >> >> >> 3.0 since I have an older Lenovo X201 with USB 2.0 ports that does > >> >> >> _not_ exhibit this problem. IOW when I connect my Arietta G25 mass > >> >> >> storage gadget to the X201, it works properly for all G25 kernels > >> >> >> that I have tried. > > > >> >> I'd blame UDC driver. We have several other UDCs working with the same > >> >> configuration. > >> > > >> > Sounds reasonable to me. But that doesn't explain why it works okay > >> > with the older Lenovo X201 laptop. > >> > >> it seems like only x240 is running > 4.0. What is x201 running ? Could > >> be older, buggy xhci driver. > > > > Or maybe it uses EHCI, since Douglas described it as having USB 2.0 > > ports. > > yeah, but 64 bytes is still wrong :-) Maybe with the EHCI host it sets the maxpacket value to 512, as it should. The xHCI driver/hardware combination still seems to have its little quirks when interacting with non-SuperSpeed devices, even though it has been around for years now. Alan Stern -- 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
