android_kernel_xiaomi_sm8350/Documentation/usb
David Brownell fbf54dd320 USB: usb/dma doc updates
This patch updates some of the documentation about DMA buffer management
for USB, and ways to avoid extra copying.  Our understanding of the issues
has improved over time.

 - Most drivers should *avoid* the dma-coherent allocators.  There are
   a few exceptions (like the HID driver).

 - Some methods are currently commented out; it seems folk writing
   USB drivers aren't doing performance tuning at that level yet.

 - Just avoid highmem; there's no good way to pass an "I can do highmem
   DMA" capability through a driver stack.  This is easy, everything
   already avoids highmem.  But it'd be nice if x86_32 systems with much
   physical memory could use it directly with network adapters and mass
   storage devices.  (Patch, anyone?)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-12 16:34:42 -07:00
..
acm.txt
auerswald.txt
CREDITS documentation: convert the Documentation directory to UTF-8 2007-05-09 08:58:19 +02:00
dma.txt USB: usb/dma doc updates 2007-07-12 16:34:42 -07:00
ehci.txt
error-codes.txt
gadget_serial.txt
hiddev.txt
hotplug.txt
linux.inf
mtouchusb.txt
ohci.txt
persist.txt USB: add power/persist device attribute 2007-07-12 16:34:30 -07:00
proc_usb_info.txt USB: indicate active altsetting in proc/bus/usb/devices file 2007-02-07 15:44:33 -08:00
rio.txt
uhci.txt
URB.txt
usb-help.txt
usb-serial.txt documentation: convert the Documentation directory to UTF-8 2007-05-09 08:58:19 +02:00
usbmon.txt usbmon: Extended text API 2007-04-27 13:28:33 -07:00