mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-14 06:24:53 +08:00
2836267312
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> |
||
---|---|---|
.. | ||
atm | ||
c67x00 | ||
chipidea | ||
class | ||
common | ||
core | ||
dwc2 | ||
dwc3 | ||
early | ||
gadget | ||
host | ||
image | ||
isp1760 | ||
misc | ||
mon | ||
musb | ||
phy | ||
renesas_usbhs | ||
serial | ||
storage | ||
usbip | ||
wusbcore | ||
Kconfig | ||
Makefile | ||
README | ||
usb-skeleton.c |
To understand all the Linux-USB framework, you'll use these resources: * This source code. This is necessarily an evolving work, and includes kerneldoc that should help you get a current overview. ("make pdfdocs", and then look at "usb.pdf" for host side and "gadget.pdf" for peripheral side.) Also, Documentation/usb has more information. * The USB 2.0 specification (from www.usb.org), with supplements such as those for USB OTG and the various device classes. The USB specification has a good overview chapter, and USB peripherals conform to the widely known "Chapter 9". * Chip specifications for USB controllers. Examples include host controllers (on PCs, servers, and more); peripheral controllers (in devices with Linux firmware, like printers or cell phones); and hard-wired peripherals like Ethernet adapters. * Specifications for other protocols implemented by USB peripheral functions. Some are vendor-specific; others are vendor-neutral but just standardized outside of the www.usb.org team. Here is a list of what each subdirectory here is, and what is contained in them. core/ - This is for the core USB host code, including the usbfs files and the hub class driver ("hub_wq"). host/ - This is for USB host controller drivers. This includes UHCI, OHCI, EHCI, and others that might be used with more specialized "embedded" systems. gadget/ - This is for USB peripheral controller drivers and the various gadget drivers which talk to them. Individual USB driver directories. A new driver should be added to the first subdirectory in the list below that it fits into. image/ - This is for still image drivers, like scanners or digital cameras. ../input/ - This is for any driver that uses the input subsystem, like keyboard, mice, touchscreens, tablets, etc. ../media/ - This is for multimedia drivers, like video cameras, radios, and any other drivers that talk to the v4l subsystem. ../net/ - This is for network drivers. serial/ - This is for USB to serial drivers. storage/ - This is for USB mass-storage drivers. class/ - This is for all USB device drivers that do not fit into any of the above categories, and work for a range of USB Class specified devices. misc/ - This is for all USB device drivers that do not fit into any of the above categories.