[PATCH 0/4] USB & USBNET: loose DMA SG check and support usbnet DMA SG

Ming Lei
2013-07-31T10:51:45Z

Hi,

This patchset allows drivers to pass sg buffers which size can't be divided
by max packet size of endpoint if the host controllers support this kind
of sg buffers.

Previously we add check[1] on the situation and don't allow these sg buffers
passed to USB HCD, looks the check is too strict because some applications(such
as network stack) can't provide this sg buffers which size can be divided by
max packet size, so this patch looses the check in case that the host controllers
support it.

Also patch 3/4 implements DMA SG on usbnet driver, and patch 4/4
enables it on ax88179_178a USB3 NIC, so CPU utilization can be
decreased much with usbnet DMA SG when the USB3 NIC is attached to
xHCI controller.

[1], http://git.kernel.org/cgit/linux/kernel/git/gregkh/usb.git/commit/?h=usb-next&id=10e232c597ac757e7f8600649f7e872e86de190f

drivers/net/usb/ax88179_178a.c | 30 +++++++++++++++++++++++++
drivers/net/usb/usbnet.c | 48 ++++++++++++++++++++++++++++++++++++++--
drivers/usb/core/urb.c | 3 ++-
drivers/usb/host/xhci.c | 4 ++++
include/linux/usb.h | 3 ++-
include/linux/usb/usbnet.h | 4 ++++
6 files changed, 88 insertions(+), 4 deletions(-)

Thanks,
--
Ming Lei

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