USB: make urb scatter-gather support more generic
The WHCI HCD will also support urbs with scatter-gather lists. Add a
usb_bus field to indicated how many sg list elements are supported by
the HCD. Use this to decide whether to pass the scatter-list to the HCD
or not.
Make the usb-storage driver use this new field.
Signed-off-by: David Vrabel <david.vrabel@csr.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index e80f1af..8d874ca 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -393,13 +393,7 @@
if (io->entries <= 0)
return io->entries;
- /* If we're running on an xHCI host controller, queue the whole scatter
- * gather list with one call to urb_enqueue(). This is only for bulk,
- * as that endpoint type does not care how the data gets broken up
- * across frames.
- */
- if (usb_pipebulk(pipe) &&
- bus_to_hcd(dev->bus)->driver->flags & HCD_USB3) {
+ if (dev->bus->sg_tablesize > 0) {
io->urbs = kmalloc(sizeof *io->urbs, mem_flags);
use_sg = true;
} else {