When a control URB is submitted, the direction indicated by URB's pipe
member is supposed to match the direction indicated by the setup
packet's bRequestType member. A mismatch could lead to trouble,
depending on which field the host controller drivers use for
determining the actual direction.
This shouldn't ever happen; it would represent a careless bug in a
kernel driver somewhere. This patch adds a dev_WARN_ONCE to let
people know about the potential problem.
Suggested-by: "Geoffrey D. Bennett" <g@xxxxx>
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
---
v2: Use dev_WARN_ONCE instead of dev_WARN
[as1960b]
drivers/usb/core/urb.c | 3 +++
1 file changed, 3 insertions(+)
Index: usb-devel/drivers/usb/core/urb.c
===================================================================
--- usb-devel.orig/drivers/usb/core/urb.c
+++ usb-devel/drivers/usb/core/urb.c
@@ -407,6 +407,9 @@ int usb_submit_urb(struct urb *urb, gfp_
return -ENOEXEC;
is_out = !(setup->bRequestType & USB_DIR_IN) ||
!setup->wLength;
+ dev_WARN_ONCE(&dev->dev, (usb_pipeout(urb->pipe) != is_out),
+ "BOGUS control dir, pipe %x doesn't match bRequestType %x\n",
+ urb->pipe, setup->bRequestType);
} else {
is_out = usb_endpoint_dir_out(&ep->desc);
}
