This patch (as1298) fixes a bug in the new scatter-gather URB
facility. If an URB uses a scatterlist then it should not have the
URB_NO_INTERRUPT flag set; otherwise the system won't be notified when
the transfer completes.
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
CC: David Vrabel <david.vrabel@xxxxxxx>
CC: Sarah Sharp <sarah.a.sharp@xxxxxxxxx>
---
Unless David or Sarah thinks otherwise, this patch can wait until
2.6.33. It affects only HCDs with scatter-gather support, which
currently means only WHCI and xHCI.
I'm a little surprised the bug hasn't shown up in testing on those
controllers, however. Is it hidden by an I/O watchdog timer? Or do
they simply not support URB_NO_INTERRUPT?
Index: usb-2.6/drivers/usb/core/message.c
===================================================================
--- usb-2.6.orig/drivers/usb/core/message.c
+++ usb-2.6/drivers/usb/core/message.c
@@ -403,7 +403,7 @@ int usb_sg_init(struct usb_sg_request *i
if (!io->urbs)
goto nomem;
- urb_flags = URB_NO_INTERRUPT;
+ urb_flags = 0;
if (dma)
urb_flags |= URB_NO_TRANSFER_DMA_MAP;
if (usb_pipein(pipe))
@@ -435,6 +435,7 @@ int usb_sg_init(struct usb_sg_request *i
io->urbs[0]->num_sgs = io->entries;
io->entries = 1;
} else {
+ urb_flags |= URB_NO_INTERRUPT;
for_each_sg(sg, sg, io->entries, i) {
unsigned len;
--
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