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Peter Chen authored
The register of ttctrl.ttha describes like below: - Internal TT Hub Address Representation - RW - Default = 0000000b This field is used to match against the Hub Address field in QH & siTD to determine if the packet is routed to the internal TT for directly attached FS/LS devices. If the Hub Address in the QH or siTD does not match this address then the packet will be broadcast on the High Speed ports destined for a downstream High Speed hub with the address in the QH/siTD. In silicon RTL, this entry only affects QH and siTD, and the hub.addr at both QH and siTD are 0 in ehci core for chipidea (with hcd->has_tt = 1). So, for QH, if the "usage_tt" flag at RTL is 0, set CI_HDRC_SET_NON_ZERO_TTHA will not affect QH (with non-hs device); for siTD, set this flag will change remaining space requirement for the last transaction from 1023 bytes to 188 bytes, it can increase the number of transactions within one frame, ehci periodic schedule code will not queue the packet if the frame space is full, so it is safe to set this flag for siTD. With this flag, it can fix the problem Alan Stern reported below: http://www.spinics.net/lists/linux-usb/msg123125.html And may fix Michael Tessier's problem too. http://www.spinics.net/lists/linux-usb/msg118679.html CC: stern@rowland.harvard.edu CC: michael.tessier@axiontech.ca Signed-off-by: Peter Chen <peter.chen@freescale.com>
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