On Tue, Jun 04, 2019 at 04:53:54PM +0800, Jim Lin wrote: > > > On 2019年06月03日 20:23, Greg KH wrote: > > On Mon, Jun 03, 2019 at 06:53:42PM +0800, Jim Lin wrote: > > > USB 2.0 specification chapter 11.17.5 says "as part of endpoint halt > > > processing for full-/low-speed endpoints connected via a TT, the host > > > software must use the Clear_TT_Buffer request to the TT to ensure > > > that the buffer is not in the busy state". > > > > > > In our case, a full-speed speaker (ConferenceCam) is behind a high- > > > speed hub (ConferenceCam Connect), sometimes once we get STALL on a > > > request we may continue to get STALL with the folllowing requests, > > > like Set_Interface. > > > > > > Solution is to invoke usb_hub_clear_tt_buffer() to send > > > Clear_TT_Buffer request to the hub of the device for the following > > > Set_Interface requests to the device to get ACK successfully. > > > > > > The Clear_TT_Buffer request sent to the hub includes the address of > > > the LS/FS child device in wValue field. usb_hub_clear_tt_buffer() > > > uses udev->devnum to set the address wValue. This won't work for > > > devices connected to xHC. > > > > > > For other host controllers udev->devnum is the same as the address of > > > the usb device, chosen and set by usb core. With xHC the controller > > > hardware assigns the address, and won't be the same as devnum. > > > > > > Here we have two patches. > > > One is to add devaddr in struct usb_device for > > > usb_hub_clear_tt_buffer() to use. > > > Another is to invoke usb_hub_clear_tt_buffer() for halt processing. > > Why did you resend patch series 11? > Didn't get response in 2 or 3 days. > Will be more patient next time. Please do, only resend if you do not get a response after 2 weeks. thanks, greg k-h
