path: root/drivers/usb/host/ehci-sched.c
diff options
authorAlan Stern <stern@rowland.harvard.edu>2013-03-22 13:30:43 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-03-25 13:35:05 -0700
commitc1fdb68e3d73741630ca16695cf9176c233be7ed (patch)
treeb256bd0c02c458730537f6d4b5b470adbce7f97b /drivers/usb/host/ehci-sched.c
parentc79041a44045a40329d9ada3f8679c4b30c5b76b (diff)
USB: EHCI: changes related to qh_refresh()
This patch (as1638) makes several changes to the ehci-hcd driver, all related to the qh_refresh() function. This function must be called whenever an idle QH gets linked back into either the async or the periodic schedule. Change a BUG_ON() in the qh_update routine to a WARN_ON(). Since this code runs in atomic context, a BUG_ON() would immediately freeze the whole system. Remove two unneeded calls to qh_refresh(), one when a QH is initialized and one when a QH becomes idle. Adjust the adjacent comments accordingly. Move the qh_refresh() and qh_link_periodic() calls for new interrupt URBs to after the new TDs have been added. As a result of the previous two changes, qh_refresh() is never called when the qtd_list is empty. The corresponding check in qh_refresh() can be removed, along with an indentation level. These changes should not cause any alteration of behavior. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host/ehci-sched.c')
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index b476daf49f6f..66259dc7822e 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -792,7 +792,6 @@ static int qh_schedule(struct ehci_hcd *ehci, struct ehci_qh *qh)
unsigned frame; /* 0..(qh->period - 1), or NO_FRAME */
struct ehci_qh_hw *hw = qh->hw;
- qh_refresh(ehci, qh);
hw->hw_next = EHCI_LIST_END(ehci);
frame = qh->start;
@@ -844,8 +843,6 @@ static int qh_schedule(struct ehci_hcd *ehci, struct ehci_qh *qh)
} else
ehci_dbg (ehci, "reused qh %p schedule\n", qh);
- /* stuff into the periodic schedule */
- qh_link_periodic(ehci, qh);
return status;
@@ -891,6 +888,12 @@ static int intr_submit (
qh = qh_append_tds(ehci, urb, qtd_list, epnum, &urb->ep->hcpriv);
BUG_ON (qh == NULL);
+ /* stuff into the periodic schedule */
+ if (qh->qh_state == QH_STATE_IDLE) {
+ qh_refresh(ehci, qh);
+ qh_link_periodic(ehci, qh);
+ }
/* ... update usbfs periodic stats */