fbf54dd320
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> |
||
|---|---|---|
| .. | ||
| acm.txt | ||
| auerswald.txt | ||
| CREDITS | ||
| dma.txt | ||
| ehci.txt | ||
| error-codes.txt | ||
| gadget_serial.txt | ||
| hiddev.txt | ||
| hotplug.txt | ||
| linux.inf | ||
| mtouchusb.txt | ||
| ohci.txt | ||
| persist.txt | ||
| proc_usb_info.txt | ||
| rio.txt | ||
| uhci.txt | ||
| URB.txt | ||
| usb-help.txt | ||
| usb-serial.txt | ||
| usbmon.txt | ||