Hi Alan, On Monday, 11 December 2023, 17:21:56 CET, Alan Stern wrote: > On Mon, Dec 11, 2023 at 11:40:38AM +0100, Christian Eggers wrote: > > Last week I upgraded within the 5.15-stable branch. Since upstream commit > > 85d07c556216 ("USB: core: Unite old scheme and new scheme descriptor reads"), > > there are problems detecting a directly attached USB hub. I identified this > > commit by bisecting and get the same result during upgrading within the 6.1-stable > > branch. > > > > Hardware: ARMv7 NXP i.MX6ULL with directly attached USB hub (Microchip USB4916). > > Log messages: > > > > [ 6.150881] usb 1-1: new high-speed USB device number 2 using ci_hdrc > > [ 6.215484] usb 1-1: device descriptor read/8, error -71 > > [ 6.377532] usb 1-1: device descriptor read/8, error -71 > > Is the old_scheme_first module parameter for the usbcore module set? > > That and the USB_PORT_QUIRK_OLD_SCHEME are the only things I can see > which would cause those errors -- and apparently this quirk never gets > set in current kernels. that was the problem! In previous attempts to reduce the boot time of my system I have set USB_PORT_QUIRK_OLD_SCHEME for specific combinations of bus/port numbers. After reverting this, the warnings don't appear anymore, so everything is fine now. Thanks for identifying the problem and sorry for the noise. regards, Christian