https://bugzilla.kernel.org/show_bug.cgi?id=208357 --- Comment #4 from Alan Stern (stern@xxxxxxxxxxxxxxxxxxx) --- Well, the problem is clear enough: Interface 5 uses endpoint 1-OUT in alternate setting 1, 1-IN in alternate setting 2, and both 1-OUT and 1-IN in alternate setting 3. At the same time, interface 7 alternate setting 1 uses endpoint 1-OUT and interface 8 alternate setting 1 uses endpoint 1-IN. According to the USB spec, different interfaces are not allowed to use the same endpoints. (The exact statement, in section 9.6.3 of the USB-2.0 specification, is: "An endpoint is not shared among interfaces within a single configuration unless the endpoint is used by alternate settings of the same interface." IMO the word "unless" should have been "except when".) This device would never pass the USB validation suite and would not be allowed to use the USB logo. Under the circumstances, it looks like interface 5 is not intended for general use, since it is described as Vendor-Specific. Does it get used in your system? The answer can be found in the /sys/kernel/debug/usb/devices file (with the device plugged in under an earlier kernel where it works okay). It may turn out that the way to deal with this problem is to add ENDPOINT_IGNORE quirks for interface 5 on this device. -- You are receiving this mail because: You are watching the assignee of the bug.
