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authorDavid S. Miller <davem@davemloft.net>2012-04-13 13:32:07 -0700
committerDavid S. Miller <davem@davemloft.net>2012-04-13 13:32:07 -0700
commit3423166fdbc2444bf3a4a27af1d7508364a17be7 (patch)
tree0a42bd5fbe6bcca79802bf1ec5af6acf12aadd82 /drivers/usb/core/urb.c
parente9b57cca3dbdc7a0b90514af8bf613baf97105a5 (diff)
parent7d93101fc71ec47c7cc66ac99f76ef795c5207aa (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc
Diffstat (limited to 'drivers/usb/core/urb.c')
-rw-r--r--drivers/usb/core/urb.c44
1 files changed, 27 insertions, 17 deletions
diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c
index 909625b91eb3..cd9b3a2cd8a7 100644
--- a/drivers/usb/core/urb.c
+++ b/drivers/usb/core/urb.c
@@ -403,20 +403,17 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags)
* cause problems in HCDs if they get it wrong.
*/
{
- unsigned int orig_flags = urb->transfer_flags;
unsigned int allowed;
static int pipetypes[4] = {
PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT
};
/* Check that the pipe's type matches the endpoint's type */
- if (usb_pipetype(urb->pipe) != pipetypes[xfertype]) {
- dev_err(&dev->dev, "BOGUS urb xfer, pipe %x != type %x\n",
+ if (usb_pipetype(urb->pipe) != pipetypes[xfertype])
+ dev_WARN(&dev->dev, "BOGUS urb xfer, pipe %x != type %x\n",
usb_pipetype(urb->pipe), pipetypes[xfertype]);
- return -EPIPE; /* The most suitable error code :-) */
- }
- /* enforce simple/standard policy */
+ /* Check against a simple/standard policy */
allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT | URB_DIR_MASK |
URB_FREE_BUFFER);
switch (xfertype) {
@@ -435,14 +432,12 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags)
allowed |= URB_ISO_ASAP;
break;
}
- urb->transfer_flags &= allowed;
+ allowed &= urb->transfer_flags;
- /* fail if submitter gave bogus flags */
- if (urb->transfer_flags != orig_flags) {
- dev_err(&dev->dev, "BOGUS urb flags, %x --> %x\n",
- orig_flags, urb->transfer_flags);
- return -EINVAL;
- }
+ /* warn if submitter gave bogus flags */
+ if (allowed != urb->transfer_flags)
+ dev_WARN(&dev->dev, "BOGUS urb flags, %x --> %x\n",
+ urb->transfer_flags, allowed);
}
#endif
/*
@@ -532,15 +527,22 @@ EXPORT_SYMBOL_GPL(usb_submit_urb);
* a driver's I/O routines to insure that all URB-related activity has
* completed before it returns.
*
- * This request is always asynchronous. Success is indicated by
- * returning -EINPROGRESS, at which time the URB will probably not yet
- * have been given back to the device driver. When it is eventually
- * called, the completion function will see @urb->status == -ECONNRESET.
+ * This request is asynchronous, however the HCD might call the ->complete()
+ * callback during unlink. Therefore when drivers call usb_unlink_urb(), they
+ * must not hold any locks that may be taken by the completion function.
+ * Success is indicated by returning -EINPROGRESS, at which time the URB will
+ * probably not yet have been given back to the device driver. When it is
+ * eventually called, the completion function will see @urb->status ==
+ * -ECONNRESET.
* Failure is indicated by usb_unlink_urb() returning any other value.
* Unlinking will fail when @urb is not currently "linked" (i.e., it was
* never submitted, or it was unlinked before, or the hardware is already
* finished with it), even if the completion handler has not yet run.
*
+ * The URB must not be deallocated while this routine is running. In
+ * particular, when a driver calls this routine, it must insure that the
+ * completion handler cannot deallocate the URB.
+ *
* Unlinking and Endpoint Queues:
*
* [The behaviors and guarantees described below do not apply to virtual
@@ -605,6 +607,10 @@ EXPORT_SYMBOL_GPL(usb_unlink_urb);
* with error -EPERM. Thus even if the URB's completion handler always
* tries to resubmit, it will not succeed and the URB will become idle.
*
+ * The URB must not be deallocated while this routine is running. In
+ * particular, when a driver calls this routine, it must insure that the
+ * completion handler cannot deallocate the URB.
+ *
* This routine may not be used in an interrupt context (such as a bottom
* half or a completion handler), or when holding a spinlock, or in other
* situations where the caller can't schedule().
@@ -642,6 +648,10 @@ EXPORT_SYMBOL_GPL(usb_kill_urb);
* with error -EPERM. Thus even if the URB's completion handler always
* tries to resubmit, it will not succeed and the URB will become idle.
*
+ * The URB must not be deallocated while this routine is running. In
+ * particular, when a driver calls this routine, it must insure that the
+ * completion handler cannot deallocate the URB.
+ *
* This routine may not be used in an interrupt context (such as a bottom
* half or a completion handler), or when holding a spinlock, or in other
* situations where the caller can't schedule().