On Tue, 4 Jun 2019, 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. > > May I get patch v11 1/2 acked or reviewed by Alan? Did I not do this already? Oh well, in any case: Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Alan Stern
