USB: EHCI: fix counting of transaction error retries

This patch (as1274) simplifies the counting of transaction-error
retries.  Now we will count up from 0 to QH_XACTERR_MAX instead of
down from QH_XACTERR_MAX to 0.

The patch also fixes a small bug: qh->xacterr was not getting
initialized for interrupt endpoints.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Matthijs Kooijman <matthijs@stdin.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 5 insertions, 5 deletions

diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index b27380505576..7673554fa64d 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -375,12 +375,11 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
                                  */
                                 if ((token & QTD_STS_XACT) &&
                                                 QTD_CERR(token) == 0 &&
-                                                --qh->xacterrs > 0 &&
+                                                ++qh->xacterrs < QH_XACTERR_MAX &&
                                                 !urb->unlinked) {
                                         ehci_dbg(ehci,
         "detected XactErr len %zu/%zu retry %d\n",
-        qtd->length - QTD_LENGTH(token), qtd->length,
-        QH_XACTERR_MAX - qh->xacterrs);
+        qtd->length - QTD_LENGTH(token), qtd->length, qh->xacterrs);
 
                                         /* reset the token in the qtd and the
                                          * qh overlay (which still contains
@@ -494,7 +493,7 @@ halt:
                 last = qtd;
 
                 /* reinit the xacterr counter for the next qtd */
-                qh->xacterrs = QH_XACTERR_MAX;
+                qh->xacterrs = 0;
         }
 
         /* last urb's completion might still need calling */
@@ -941,7 +940,7 @@ static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
         head->hw_next = dma;
 
         qh_get(qh);
-        qh->xacterrs = QH_XACTERR_MAX;
+        qh->xacterrs = 0;
         qh->qh_state = QH_STATE_LINKED;
         /* qtd completions reported later by interrupt */
 }
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 74f7f83b29ad..edd61ee90323 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -542,6 +542,7 @@ static int qh_link_periodic (struct ehci_hcd *ehci, struct ehci_qh *qh)
                 }
         }
         qh->qh_state = QH_STATE_LINKED;
+        qh->xacterrs = 0;
         qh_get (qh);
 
         /* update per-qh bandwidth for usbfs */