2 files changed, 19 insertions, 10 deletions

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 2e704fa3cedf..34a928d3b7d2 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -79,7 +79,13 @@ static const char	hcd_name [] = "ehci_hcd";
 #define EHCI_TUNE_RL_TT         0
 #define EHCI_TUNE_MULT_HS       1       /* 1-3 transactions/uframe; 4.10.3 */
 #define EHCI_TUNE_MULT_TT       1
-#define EHCI_TUNE_FLS           2       /* (small) 256 frame schedule */
+/*
+ * Some drivers think it's safe to schedule isochronous transfers more than
+ * 256 ms into the future (partly as a result of an old bug in the scheduling
+ * code).  In an attempt to avoid trouble, we will use a minimum scheduling
+ * length of 512 frames instead of 256.
+ */
+#define EHCI_TUNE_FLS           1       /* (medium) 512-frame schedule */
 
 #define EHCI_IAA_MSECS          10              /* arbitrary */
 #define EHCI_IO_JIFFIES         (HZ/10)         /* io watchdog > irq_thresh */
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 27dd841b9aa2..dd37350170bb 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -1395,28 +1395,31 @@ iso_stream_schedule (
         struct ehci_iso_stream  *stream
 )
 {
-        u32                     now, next, start, period;
+        u32                     now, next, start, period, span;
         int                     status;
         unsigned                mod = ehci->periodic_size << 3;
         struct ehci_iso_sched   *sched = urb->hcpriv;
 
-        if (sched->span > (mod - SCHEDULE_SLOP)) {
+        period = urb->interval;
+        span = sched->span;
+        if (!stream->highspeed) {
+                period <<= 3;
+                span <<= 3;
+        }
+
+        if (span > mod - SCHEDULE_SLOP) {
                 ehci_dbg (ehci, "iso request %p too long\n", urb);
                 status = -EFBIG;
                 goto fail;
         }
 
-        if ((stream->depth + sched->span) > mod) {
+        if (stream->depth + span > mod) {
                 ehci_dbg (ehci, "request %p would overflow (%d+%d>%d)\n",
-                        urb, stream->depth, sched->span, mod);
+                        urb, stream->depth, span, mod);
                 status = -EFBIG;
                 goto fail;
         }
 
-        period = urb->interval;
-        if (!stream->highspeed)
-                period <<= 3;
-
         now = ehci_readl(ehci, &ehci->regs->frame_index) & (mod - 1);
 
         /* Typical case: reuse current schedule, stream is still active.
@@ -1445,7 +1448,7 @@ iso_stream_schedule (
                                         period);
 
                 /* Tried to schedule too far into the future? */
-                if (unlikely(((start - now) & (mod - 1)) + sched->span
+                if (unlikely(((start - now) & (mod - 1)) + span
                                         >= mod - 2 * SCHEDULE_SLOP)) {
                         status = -EFBIG;
                         goto fail;