On Thu, Aug 10, 2023, Alan Stern wrote: > On Wed, Aug 09, 2023 at 09:47:14PM -0400, Alan Stern wrote: > > On Thu, Aug 10, 2023 at 12:28:27AM +0000, Thinh Nguyen wrote: > > > > Testing from Greg's usb-next branch, this series causes problem with > > > device enumeration: > > > > > > [ 31.650759] usb 2-1: new SuperSpeed Plus Gen 2x1 USB device number 2 using xhci_hcd > > > [ 31.663107] usb 2-1: device descriptor read/8, error -71 > > > [ 31.952697] usb 2-1: new SuperSpeed Plus Gen 2x1 USB device number 3 using xhci_hcd > > > [ 31.965122] usb 2-1: device descriptor read/8, error -71 > > > [ 32.080991] usb usb2-port1: attempt power cycle > > > [ 34.826893] usb 2-1: new SuperSpeed Plus Gen 2x1 USB device number 5 using xhci_hcd > > > [ 34.839241] usb 2-1: device descriptor read/8, error -71 > > > [ 35.129908] usb 2-1: new SuperSpeed Plus Gen 2x1 USB device number 6 using xhci_hcd > > > [ 35.142264] usb 2-1: device descriptor read/8, error -71 > > > [ 35.257155] usb usb2-port1: attempt power cycle > > > [ 37.258922] usb 1-1: new high-speed USB device number 5 using xhci_hcd > > > [ 38.115053] usb 2-1: new SuperSpeed Plus Gen 2x1 USB device number 8 using xhci_hcd > > > [ 38.127407] usb 2-1: device descriptor read/8, error -71 > > > [ 38.417066] usb 2-1: new SuperSpeed Plus Gen 2x1 USB device number 9 using xhci_hcd > > > [ 38.429428] usb 2-1: device descriptor read/8, error -71 > > > [ 38.545315] usb usb2-port1: attempt power cycle > > > [ 43.347312] usb 2-2: new SuperSpeed Plus Gen 2x1 USB device number 11 using xhci_hcd > > > [ 43.359659] usb 2-2: device descriptor read/8, error -71 > > > [ 43.649323] usb 2-2: new SuperSpeed Plus Gen 2x1 USB device number 12 using xhci_hcd > > > [ 43.661681] usb 2-2: device descriptor read/8, error -71 > > > [ 43.777566] usb usb2-port2: attempt power cycle > > > > > > I was testing with our host along with other common vendor hosts with a > > > few 3.x devices. Reverting this series resolves the issue. I didn't do > > > extensive tests for various speeds or debug it. I just want to notify > > > this first perhaps you can figure out the issue right away. > > > > > > I can look into it and provide more info later this week. If you want to > > > print any debug, let me know and I can provide later this week. > > > > Thanks for the notification. The problem is almost certainly caused by > > the first patch in the series, which changes the way that the initial > > read/8 thing is done. However, I have no idea what part of the patch > > could be causing these errors. I would appreciate anything you can find > > out. > > > > You should concentrate your initial investigation on the new > > get_bMaxPacketSize0() routine. In particular, does the -EPROTO error > > value arise as the return value from the usb_control_msg() call, or does > > it happen because of the values stored in buf? In the first case, how > > does this call differ from the one that used to be made by > > usb_get_device_descriptor()? And in the second case, what are the > > values of rc, buf->bMaxPacketSize0, and buf->bDescriptorType? > > Never mind; I found the problem. I had forgotten that at SuperSpeed or > faster, the device descriptor uses a logarithmic encoding for > bMaxPacketSize0. > > The patch below should fix things up. Let me know how it goes. > Quick test for Gen 1 and 2 devices work fine now. Highspeed also works as expected before. I didn't test Fullspeed with various MPS, but I don't expect any problem looking at the change. Thanks for the fix, Thinh
