On Tue, Feb 23, 2010 at 12:48 AM, Yuhong Bao <yuhongbao_386@xxxxxxxxxxx> wrote: > >> According to one Microsoft page I saw, Windows XP did not implement >> the 64-bit addressing feature in EHCI. I haven't found any information >> on whether any newer Windows versions do or not. > Windows 7 seems to support it, and it seems like they have to already do a workaround for broken NVIDIA chipsets: > http://support.microsoft.com/?kbid=976972 > http://www.windows7tipsonline.com/USB_Problem.htm > http://social.technet.microsoft.com/Forums/en-US/w7itprohardware/thread/3aae3b66-6a1a-47e8-ad1b-b20b68eaecf8#79ea3219-d76e-40bc-b910-c7d347002e66 > http://social.technet.microsoft.com/Forums/en-US/w7itprohardware/thread/38f25c1d-de67-4c74-8845-2cd3a15d8e41 That's good news actually.. it means they've apparently already debugged the feature for us :-) I suppose the next step would be to contact NVIDIA and see what they say (i.e. which particular chipsets have the problem), but from my experience with them, requests of the form "can you confirm X is a bug in your chipset" to those guys seem to go into the bit bucket. Does anyone have any good contacts at NVIDIA for USB or other chipset issues? I see there's some existing NVIDIA-specific EHCI quirks so I'm assuming someone was in contact with them before.. The fact that Windows 7 is now using the feature also means that there aren't likely to be too many machines where the 64-bit addressing is reported but doesn't work. Which means that aside from the NVIDIA quirk, I think enabling 64-bit addressing should be relatively safe. -- 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