1 files changed, 40 insertions, 16 deletions

diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 2abf8543f083..56a32033adb3 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -36,6 +36,27 @@
 
 static int ehci_get_frame (struct usb_hcd *hcd);
 
+#ifdef CONFIG_PCI
+
+static unsigned ehci_read_frame_index(struct ehci_hcd *ehci)
+{
+        unsigned uf;
+
+        /*
+         * The MosChip MCS9990 controller updates its microframe counter
+         * a little before the frame counter, and occasionally we will read
+         * the invalid intermediate value.  Avoid problems by checking the
+         * microframe number (the low-order 3 bits); if they are 0 then
+         * re-read the register to get the correct value.
+         */
+        uf = ehci_readl(ehci, &ehci->regs->frame_index);
+        if (unlikely(ehci->frame_index_bug && ((uf & 7) == 0)))
+                uf = ehci_readl(ehci, &ehci->regs->frame_index);
+        return uf;
+}
+
+#endif
+
 /*-------------------------------------------------------------------------*/
 
 /*
@@ -479,10 +500,9 @@ static int enable_periodic (struct ehci_hcd *ehci)
         cmd = ehci_readl(ehci, &ehci->regs->command) | CMD_PSE;
         ehci_writel(ehci, cmd, &ehci->regs->command);
         /* posted write ... PSS happens later */
-        ehci_to_hcd(ehci)->state = HC_STATE_RUNNING;
 
         /* make sure ehci_work scans these */
-        ehci->next_uframe = ehci_readl(ehci, &ehci->regs->frame_index)
+        ehci->next_uframe = ehci_read_frame_index(ehci)
                 % (ehci->periodic_size << 3);
         if (unlikely(ehci->broken_periodic))
                 ehci->last_periodic_enable = ktime_get_real();
@@ -677,7 +697,7 @@ static void intr_deschedule (struct ehci_hcd *ehci, struct ehci_qh *qh)
 
         /* reschedule QH iff another request is queued */
         if (!list_empty(&qh->qtd_list) &&
-                        HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) {
+                        ehci->rh_state == EHCI_RH_RUNNING) {
                 rc = qh_schedule(ehci, qh);
 
                 /* An error here likely indicates handshake failure
@@ -1409,7 +1429,7 @@ iso_stream_schedule (
                 goto fail;
         }
 
-        now = ehci_readl(ehci, &ehci->regs->frame_index) & (mod - 1);
+        now = ehci_read_frame_index(ehci) & (mod - 1);
 
         /* Typical case: reuse current schedule, stream is still active.
          * Hopefully there are no gaps from the host falling behind
@@ -1459,10 +1479,15 @@ iso_stream_schedule (
 
                 /* NOTE:  assumes URB_ISO_ASAP, to limit complexity/bugs */
 
-                /* find a uframe slot with enough bandwidth */
-                next = start + period;
-                for (; start < next; start++) {
-
+                /* find a uframe slot with enough bandwidth.
+                 * Early uframes are more precious because full-speed
+                 * iso IN transfers can't use late uframes,
+                 * and therefore they should be allocated last.
+                 */
+                next = start;
+                start += period;
+                do {
+                        start--;
                         /* check schedule: enough space? */
                         if (stream->highspeed) {
                                 if (itd_slot_ok(ehci, mod, start,
@@ -1475,7 +1500,7 @@ iso_stream_schedule (
                                                 start, sched, period))
                                         break;
                         }
-                }
+                } while (start > next);
 
                 /* no room in the schedule */
                 if (start == next) {
@@ -2275,8 +2300,8 @@ scan_periodic (struct ehci_hcd *ehci)
          * Touches as few pages as possible:  cache-friendly.
          */
         now_uframe = ehci->next_uframe;
-        if (HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) {
-                clock = ehci_readl(ehci, &ehci->regs->frame_index);
+        if (ehci->rh_state == EHCI_RH_RUNNING) {
+                clock = ehci_read_frame_index(ehci);
                 clock_frame = (clock >> 3) & (ehci->periodic_size - 1);
         } else  {
                 clock = now_uframe + mod - 1;
@@ -2310,7 +2335,7 @@ restart:
                         union ehci_shadow       temp;
                         int                     live;
 
-                        live = HC_IS_RUNNING (ehci_to_hcd(ehci)->state);
+                        live = (ehci->rh_state == EHCI_RH_RUNNING);
                         switch (hc32_to_cpu(ehci, type)) {
                         case Q_TYPE_QH:
                                 /* handle any completions */
@@ -2435,7 +2460,7 @@ restart:
                  * We can't advance our scan without collecting the ISO
                  * transfers that are still pending in this frame.
                  */
-                if (incomplete && HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) {
+                if (incomplete && ehci->rh_state == EHCI_RH_RUNNING) {
                         ehci->next_uframe = now_uframe;
                         break;
                 }
@@ -2451,12 +2476,11 @@ restart:
                 if (now_uframe == clock) {
                         unsigned        now;
 
-                        if (!HC_IS_RUNNING (ehci_to_hcd(ehci)->state)
+                        if (ehci->rh_state != EHCI_RH_RUNNING
                                         || ehci->periodic_sched == 0)
                                 break;
                         ehci->next_uframe = now_uframe;
-                        now = ehci_readl(ehci, &ehci->regs->frame_index) &
-                                        (mod - 1);
+                        now = ehci_read_frame_index(ehci) & (mod - 1);
                         if (now_uframe == now)
                                 break;