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authorRob Walker <rob@tenfoot.org.uk>2008-05-11 21:14:18 +0100
committerDaniel Drake <dsd@gentoo.org>2008-05-11 21:17:03 +0100
commite25d590a9198995b4f0b6afeb41ecae318715e7e (patch)
tree5c02a1fea2740776a8cad5b4d59a1bb56cc0d726 /libusb/os/linux_usbfs.c
parentfec7c84163e25b8f811632828334d75da82bcb16 (diff)
downloadlibusb-e25d590a9198995b4f0b6afeb41ecae318715e7e.tar.gz
Linux: fix bulk transfer early completion
We were forgetting about the remaining urbs when a non-final urb completed early. [dsd: some touchups and a warning message for a corner case that we don't handle]
Diffstat (limited to 'libusb/os/linux_usbfs.c')
-rw-r--r--libusb/os/linux_usbfs.c49
1 files changed, 42 insertions, 7 deletions
diff --git a/libusb/os/linux_usbfs.c b/libusb/os/linux_usbfs.c
index e3aa7a9..edf1545 100644
--- a/libusb/os/linux_usbfs.c
+++ b/libusb/os/linux_usbfs.c
@@ -85,6 +85,9 @@ enum reap_action {
/* cancelled by user or timeout */
CANCELLED,
+
+ /* completed multi-URB transfer in non-final URB */
+ COMPLETED_EARLY,
};
struct linux_transfer_priv {
@@ -1510,7 +1513,7 @@ static int handle_bulk_completion(struct usbi_transfer *itransfer,
struct linux_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
int num_urbs = tpriv->num_urbs;
int urb_idx = urb - tpriv->urbs;
- enum libusb_transfer_status status;
+ enum libusb_transfer_status status = LIBUSB_TRANSFER_COMPLETED;
usbi_dbg("handling completion status %d of bulk urb %d/%d", urb->status,
urb_idx + 1, num_urbs);
@@ -1518,7 +1521,8 @@ static int handle_bulk_completion(struct usbi_transfer *itransfer,
if (urb->status == 0)
itransfer->transferred += urb->actual_length;
- if (tpriv->reap_action != NORMAL) { /* cancelled or submit_fail */
+ if (tpriv->reap_action != NORMAL) {
+ /* cancelled, submit_fail, or completed early */
if (urb->status == -ENOENT) {
usbi_dbg("CANCEL: detected a cancelled URB");
if (tpriv->awaiting_discard == 0)
@@ -1527,6 +1531,13 @@ static int handle_bulk_completion(struct usbi_transfer *itransfer,
tpriv->awaiting_discard--;
} else if (urb->status == 0) {
usbi_dbg("CANCEL: detected a completed URB");
+
+ /* FIXME we could solve this extreme corner case with a memmove
+ * or something */
+ if (tpriv->reap_action == COMPLETED_EARLY)
+ usbi_warn("SOME DATA LOST! (completed early but remaining "
+ "urb completed)");
+
if (tpriv->awaiting_reap == 0)
usbi_err("CANCEL: completed URB not awaiting reap?");
else
@@ -1537,9 +1548,12 @@ static int handle_bulk_completion(struct usbi_transfer *itransfer,
if (tpriv->awaiting_reap == 0 && tpriv->awaiting_discard == 0) {
usbi_dbg("CANCEL: last URB handled, reporting");
- free(tpriv->urbs);
if (tpriv->reap_action == CANCELLED) {
usbi_handle_transfer_cancellation(itransfer);
+ free(tpriv->urbs);
+ return 0;
+ } else if (tpriv->reap_action == COMPLETED_EARLY) {
+ goto out;
} else {
status = LIBUSB_TRANSFER_ERROR;
goto out;
@@ -1558,17 +1572,38 @@ static int handle_bulk_completion(struct usbi_transfer *itransfer,
/* if we're the last urb or we got less data than requested then we're
* done */
- if (urb_idx == num_urbs - 1)
+ if (urb_idx == num_urbs - 1) {
usbi_dbg("last URB in transfer --> complete!");
- else if (urb->actual_length < urb->buffer_length)
+ } else if (urb->actual_length < urb->buffer_length) {
+ struct libusb_transfer *transfer =
+ __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+ struct linux_device_handle_priv *dpriv =
+ __device_handle_priv(transfer->dev_handle);
+ int i;
+
usbi_dbg("short transfer %d/%d --> complete!",
urb->actual_length, urb->buffer_length);
- else
+
+ /* we have to cancel the remaining urbs and wait for their completion
+ * before reporting results */
+ tpriv->reap_action = COMPLETED_EARLY;
+ for (i = urb_idx + 1; i < tpriv->num_urbs; i++) {
+ int r = ioctl(dpriv->fd, IOCTL_USBFS_DISCARDURB, &tpriv->urbs[i]);
+ if (r == 0)
+ tpriv->awaiting_discard++;
+ else if (r == -EINVAL)
+ tpriv->awaiting_reap++;
+ else
+ usbi_warn("unrecognised discard return %d", r);
+ }
return 0;
+ } else {
+ return 0;
+ }
out:
free(tpriv->urbs);
- usbi_handle_transfer_completion(itransfer, LIBUSB_TRANSFER_COMPLETED);
+ usbi_handle_transfer_completion(itransfer, status);
return 0;
}