diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2013-03-22 13:30:43 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-25 13:35:05 -0700 |
| commit | c1fdb68e3d73741630ca16695cf9176c233be7ed (patch) | |
| tree | b256bd0c02c458730537f6d4b5b470adbce7f97b /drivers/usb/host/ehci-sched.c | |
| parent | c79041a44045a40329d9ada3f8679c4b30c5b76b (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')
| -rw-r--r-- | drivers/usb/host/ehci-sched.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c index b476daf49f6..66259dc7822 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); done: 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 */ ehci_to_hcd(ehci)->self.bandwidth_int_reqs++; |