bba787a860
USB network adapters support Jumbo frames. The only thing blocking that feature is the code in the gadget driver that disposes of packets larger than 1518 bytes, and the limit on the ioctl to set the mtu. This patch relaxes these limits, and allows up to 15k frames sizes. The 15k value was chosen because 16k does not work on all platforms, and usingclose to 16k will result in allocating 5 or 8 4k pages to store the skb, wasting pages at no measurable performance gain. On a topic-miami board (Zynq-7000), iperf3 performance reports: MTU= 1500, PC-to-gadget: 139 Mbps, Gadget-to-PC: 116 Mbps MTU=15000, PC-to-gadget: 239 Mbps, Gadget-to-PC: 361 Mbps On boards with slower CPUs the performance improvement will be relatively much larger, e.g. an OMAP-L138 increased from 40 to 220 Mbps using a similar patch on an 2.6.37 kernel. Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl> Signed-off-by: Felipe Balbi <balbi@ti.com> |
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.. | ||
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.