From: Matt Evans <matt@ozlabs.org>
To: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: linuxppc-dev@ozlabs.org, linux-usb@vger.kernel.org
Subject: [PATCH v3 4/4] xhci: Remove recursive call to xhci_handle_event
Date: Tue, 29 Mar 2011 13:41:02 +1100 [thread overview]
Message-ID: <4D9146BE.4080306@ozlabs.org> (raw)
Make the caller loop while there are events to handle, instead.
Signed-off-by: Matt Evans <matt@ozlabs.org>
---
Added a comment on the return value, defining <0 to be 'bad'.
drivers/usb/host/xhci-ring.c | 18 +++++++++++-------
1 files changed, 11 insertions(+), 7 deletions(-)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 86c8198..5fce46c 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2128,8 +2128,10 @@ cleanup:
/*
* This function handles all OS-owned events on the event ring. It may drop
* xhci->lock between event processing (e.g. to pass up port status changes).
+ * Returns >0 for "possibly more events to process" (caller should call again),
+ * otherwise 0 if done. In future, <0 returns should indicate error code.
*/
-static void xhci_handle_event(struct xhci_hcd *xhci)
+static int xhci_handle_event(struct xhci_hcd *xhci)
{
union xhci_trb *event;
int update_ptrs = 1;
@@ -2138,7 +2140,7 @@ static void xhci_handle_event(struct xhci_hcd *xhci)
xhci_dbg(xhci, "In %s\n", __func__);
if (!xhci->event_ring || !xhci->event_ring->dequeue) {
xhci->error_bitmask |= 1 << 1;
- return;
+ return 0;
}
event = xhci->event_ring->dequeue;
@@ -2146,7 +2148,7 @@ static void xhci_handle_event(struct xhci_hcd *xhci)
if ((le32_to_cpu(event->event_cmd.flags) & TRB_CYCLE) !=
xhci->event_ring->cycle_state) {
xhci->error_bitmask |= 1 << 2;
- return;
+ return 0;
}
xhci_dbg(xhci, "%s - OS owns TRB\n", __func__);
@@ -2190,15 +2192,17 @@ static void xhci_handle_event(struct xhci_hcd *xhci)
if (xhci->xhc_state & XHCI_STATE_DYING) {
xhci_dbg(xhci, "xHCI host dying, returning from "
"event handler.\n");
- return;
+ return 0;
}
if (update_ptrs)
/* Update SW event ring dequeue pointer */
inc_deq(xhci, xhci->event_ring, true);
- /* Are there more items on the event ring? */
- xhci_handle_event(xhci);
+ /* Are there more items on the event ring? Caller will call us again to
+ * check.
+ */
+ return 1;
}
/*
@@ -2280,7 +2284,7 @@ hw_died:
/* FIXME this should be a delayed service routine
* that clears the EHB.
*/
- xhci_handle_event(xhci);
+ while (xhci_handle_event(xhci) > 0) {}
temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
/* If necessary, update the HW's version of the event ring deq ptr. */
--
1.7.0.4
reply other threads:[~2011-03-29 2:41 UTC|newest]
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