USB: EHCI: change return value of qh_completions()
This patch (as1658) cleans up the usage of qh_completions() in
ehci-hcd. Currently the function's return value indicates whether any
URBs were given back; the idea was that the caller can scan the QH
over again to handle any URBs that were dequeued by a completion
handler. This is not necessary; when qh_completions() is ready to
give back dequeued URBs, it does its own rescanning.
Therefore the new return value will be a flag indicating whether the
caller needs to unlink the QH. This is more convenient than forcing
the caller to check qh->needs_rescan, and it makes a lot more sense --
why should "needs_rescan" imply that an unlink is needed? The callers
are also changed to remove the unneeded rescans.
Lastly, the check for whether qh->qtd_list is non-empty is removed
from the start of qh_completions(). Two of the callers have to make
this test anyway, so the same test can simply be added to the other
two callers.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 66259dc..5c82bba 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -649,7 +649,8 @@
qh->qh_state = QH_STATE_IDLE;
hw->hw_next = EHCI_LIST_END(ehci);
- qh_completions(ehci, qh);
+ if (!list_empty(&qh->qtd_list))
+ qh_completions(ehci, qh);
/* reschedule QH iff another request is queued */
if (!list_empty(&qh->qtd_list) && ehci->rh_state == EHCI_RH_RUNNING) {
@@ -914,7 +915,7 @@
list_for_each_entry_safe(qh, ehci->qh_scan_next, &ehci->intr_qh_list,
intr_node) {
- rescan:
+
/* clean any finished work for this qh */
if (!list_empty(&qh->qtd_list)) {
int temp;
@@ -927,12 +928,9 @@
* in qh_unlink_periodic().
*/
temp = qh_completions(ehci, qh);
- if (unlikely(qh->needs_rescan ||
- (list_empty(&qh->qtd_list) &&
- qh->qh_state == QH_STATE_LINKED)))
+ if (unlikely(temp || (list_empty(&qh->qtd_list) &&
+ qh->qh_state == QH_STATE_LINKED)))
start_unlink_intr(ehci, qh);
- else if (temp != 0)
- goto rescan;
}
}
}