USB: ehci: Respect IST when scheduling new split iTDs.

[linux-imx.git] / drivers / usb / host / ehci-sched.c

diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 84079ebbe656b3bef85fed1ebbd9168d0caf6e22..1e391e624c8affee6e58d699de953df4bcaa857a 100644 (file)
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -1394,10 +1394,11 @@ iso_stream_schedule (
        struct ehci_iso_stream  *stream
 )
 {
-       u32                     now, start, max, period;
+       u32                     now, next, start, period;
        int                     status;
        unsigned                mod = ehci->periodic_size << 3;
        struct ehci_iso_sched   *sched = urb->hcpriv;
+       struct pci_dev          *pdev;
 
        if (sched->span > (mod - SCHEDULE_SLOP)) {
                ehci_dbg (ehci, "iso request %p too long\n", urb);
@@ -1418,26 +1419,35 @@ iso_stream_schedule (
 
        now = ehci_readl(ehci, &ehci->regs->frame_index) % mod;
 
-       /* when's the last uframe this urb could start? */
-       max = now + mod;
-
        /* Typical case: reuse current schedule, stream is still active.
         * Hopefully there are no gaps from the host falling behind
         * (irq delays etc), but if there are we'll take the next
         * slot in the schedule, implicitly assuming URB_ISO_ASAP.
         */
        if (likely (!list_empty (&stream->td_list))) {
+               pdev = to_pci_dev(ehci_to_hcd(ehci)->self.controller);
                start = stream->next_uframe;
-               if (start < now)
-                       start += mod;
+
+               /* For high speed devices, allow scheduling within the
+                * isochronous scheduling threshold.  For full speed devices,
+                * don't. (Work around for Intel ICH9 bug.)
+                */
+               if (!stream->highspeed &&
+                               pdev->vendor == PCI_VENDOR_ID_INTEL)
+                       next = now + ehci->i_thresh;
+               else
+                       next = now;
 
                /* Fell behind (by up to twice the slop amount)? */
-               if (start >= max - 2 * SCHEDULE_SLOP)
+               if (((start - next) & (mod - 1)) >=
+                               mod - 2 * SCHEDULE_SLOP)
                        start += period * DIV_ROUND_UP(
-                                       max - start, period) - mod;
+                                       (next - start) & (mod - 1),
+                                       period);
 
                /* Tried to schedule too far into the future? */
-               if (unlikely((start + sched->span) >= max)) {
+               if (unlikely(((start - now) & (mod - 1)) + sched->span
+                                       >= mod - 2 * SCHEDULE_SLOP)) {
                        status = -EFBIG;
                        goto fail;
                }
@@ -1482,7 +1492,7 @@ iso_stream_schedule (
        /* no room in the schedule */
        ehci_dbg (ehci, "iso %ssched full %p (now %d max %d)\n",
                list_empty (&stream->td_list) ? "" : "re",
-               urb, now, max);
+               urb, now, now + mod);
        status = -ENOSPC;
 
 fail: