Merge branch 'release-2.6.27' of git://git.kernel.org/pub/scm/linux/kernel/git/ak...
[pandora-kernel.git] / drivers / usb / host / ehci-q.c
index 776a97f..2622b65 100644 (file)
@@ -242,7 +242,8 @@ __acquires(ehci->lock)
        if (unlikely(urb->unlinked)) {
                COUNT(ehci->stats.unlink);
        } else {
-               if (likely(status == -EINPROGRESS))
+               /* report non-error and short read status as zero */
+               if (status == -EINPROGRESS || status == -EREMOTEIO)
                        status = 0;
                COUNT(ehci->stats.complete);
        }
@@ -250,7 +251,7 @@ __acquires(ehci->lock)
 #ifdef EHCI_URB_TRACE
        ehci_dbg (ehci,
                "%s %s urb %p ep%d%s status %d len %d/%d\n",
-               __FUNCTION__, urb->dev->devpath, urb,
+               __func__, urb->dev->devpath, urb,
                usb_pipeendpoint (urb->pipe),
                usb_pipein (urb->pipe) ? "in" : "out",
                status,
@@ -283,9 +284,8 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
        int                     last_status = -EINPROGRESS;
        int                     stopped;
        unsigned                count = 0;
-       int                     do_status = 0;
        u8                      state;
-       u32                     halt = HALT_BIT(ehci);
+       __le32                  halt = HALT_BIT(ehci);
 
        if (unlikely (list_empty (&qh->qtd_list)))
                return count;
@@ -309,7 +309,6 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
                struct ehci_qtd *qtd;
                struct urb      *urb;
                u32             token = 0;
-               int             qtd_status;
 
                qtd = list_entry (entry, struct ehci_qtd, qtd_list);
                urb = qtd->urb;
@@ -319,10 +318,10 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
                        if (likely (last->urb != urb)) {
                                ehci_urb_done(ehci, last->urb, last_status);
                                count++;
+                               last_status = -EINPROGRESS;
                        }
                        ehci_qtd_free (ehci, last);
                        last = NULL;
-                       last_status = -EINPROGRESS;
                }
 
                /* ignore urbs submitted during completions we reported */
@@ -336,11 +335,20 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
                /* always clean up qtds the hc de-activated */
                if ((token & QTD_STS_ACTIVE) == 0) {
 
+                       /* on STALL, error, and short reads this urb must
+                        * complete and all its qtds must be recycled.
+                        */
                        if ((token & QTD_STS_HALT) != 0) {
                                stopped = 1;
 
                        /* magic dummy for some short reads; qh won't advance.
                         * that silicon quirk can kick in with this dummy too.
+                        *
+                        * other short reads won't stop the queue, including
+                        * control transfers (status stage handles that) or
+                        * most other single-qtd reads ... the queue stops if
+                        * URB_SHORT_NOT_OK was set so the driver submitting
+                        * the urbs could clean it up.
                         */
                        } else if (IS_SHORT_READ (token)
                                        && !(qtd->hw_alt_next
@@ -354,28 +362,21 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
                                && HC_IS_RUNNING (ehci_to_hcd(ehci)->state))) {
                        break;
 
+               /* scan the whole queue for unlinks whenever it stops */
                } else {
                        stopped = 1;
 
-                       if (unlikely (!HC_IS_RUNNING (ehci_to_hcd(ehci)->state)))
+                       /* cancel everything if we halt, suspend, etc */
+                       if (!HC_IS_RUNNING(ehci_to_hcd(ehci)->state))
                                last_status = -ESHUTDOWN;
 
-                       /* ignore active urbs unless some previous qtd
-                        * for the urb faulted (including short read) or
-                        * its urb was canceled.  we may patch qh or qtds.
+                       /* this qtd is active; skip it unless a previous qtd
+                        * for its urb faulted, or its urb was canceled.
                         */
-                       if (likely(last_status == -EINPROGRESS &&
-                                       !urb->unlinked))
-                               continue;
-
-                       /* issue status after short control reads */
-                       if (unlikely (do_status != 0)
-                                       && QTD_PID (token) == 0 /* OUT */) {
-                               do_status = 0;
+                       else if (last_status == -EINPROGRESS && !urb->unlinked)
                                continue;
-                       }
 
-                       /* token in overlay may be most current */
+                       /* qh unlinked; token in overlay may be most current */
                        if (state == QH_STATE_IDLE
                                        && cpu_to_hc32(ehci, qtd->qtd_dma)
                                                == qh->hw_current)
@@ -392,21 +393,32 @@ halt:
                        }
                }
 
-               /* remove it from the queue */
-               qtd_status = qtd_copy_status(ehci, urb, qtd->length, token);
-               if (unlikely(qtd_status == -EREMOTEIO)) {
-                       do_status = (!urb->unlinked &&
-                                       usb_pipecontrol(urb->pipe));
-                       qtd_status = 0;
+               /* unless we already know the urb's status, collect qtd status
+                * and update count of bytes transferred.  in common short read
+                * cases with only one data qtd (including control transfers),
+                * queue processing won't halt.  but with two or more qtds (for
+                * example, with a 32 KB transfer), when the first qtd gets a
+                * short read the second must be removed by hand.
+                */
+               if (last_status == -EINPROGRESS) {
+                       last_status = qtd_copy_status(ehci, urb,
+                                       qtd->length, token);
+                       if (last_status == -EREMOTEIO
+                                       && (qtd->hw_alt_next
+                                               & EHCI_LIST_END(ehci)))
+                               last_status = -EINPROGRESS;
                }
-               if (likely(last_status == -EINPROGRESS))
-                       last_status = qtd_status;
 
+               /* if we're removing something not at the queue head,
+                * patch the hardware queue pointer.
+                */
                if (stopped && qtd->qtd_list.prev != &qh->qtd_list) {
                        last = list_entry (qtd->qtd_list.prev,
                                        struct ehci_qtd, qtd_list);
                        last->hw_next = qtd->hw_next;
                }
+
+               /* remove qtd; it's recycled after possible urb completion */
                list_del (&qtd->qtd_list);
                last = qtd;
        }
@@ -431,7 +443,15 @@ halt:
                        qh_refresh(ehci, qh);
                        break;
                case QH_STATE_LINKED:
-                       /* should be rare for periodic transfers,
+                       /* We won't refresh a QH that's linked (after the HC
+                        * stopped the queue).  That avoids a race:
+                        *  - HC reads first part of QH;
+                        *  - CPU updates that first part and the token;
+                        *  - HC reads rest of that QH, including token
+                        * Result:  HC gets an inconsistent image, and then
+                        * DMAs to/from the wrong memory (corrupting it).
+                        *
+                        * That should be rare for interrupt transfers,
                         * except maybe high bandwidth ...
                         */
                        if ((cpu_to_hc32(ehci, QH_SMASK)
@@ -549,6 +569,12 @@ qh_urb_transaction (
                this_qtd_len = qtd_fill(ehci, qtd, buf, len, token, maxpacket);
                len -= this_qtd_len;
                buf += this_qtd_len;
+
+               /*
+                * short reads advance to a "magic" dummy instead of the next
+                * qtd ... that forces the queue to stop, for manual cleanup.
+                * (this will usually be overridden later.)
+                */
                if (is_input)
                        qtd->hw_alt_next = ehci->async->hw_alt_next;
 
@@ -568,8 +594,10 @@ qh_urb_transaction (
                list_add_tail (&qtd->qtd_list, head);
        }
 
-       /* unless the bulk/interrupt caller wants a chance to clean
-        * up after short reads, hc should advance qh past this urb
+       /*
+        * unless the caller requires manual cleanup after short reads,
+        * have the alt_next mechanism keep the queue running after the
+        * last data qtd (the only one, for control and most other cases).
         */
        if (likely ((urb->transfer_flags & URB_SHORT_NOT_OK) == 0
                                || usb_pipecontrol (urb->pipe)))
@@ -657,6 +685,14 @@ qh_make (
        type = usb_pipetype (urb->pipe);
        maxp = usb_maxpacket (urb->dev, urb->pipe, !is_input);
 
+       /* 1024 byte maxpacket is a hardware ceiling.  High bandwidth
+        * acts like up to 3KB, but is built from smaller packets.
+        */
+       if (max_packet(maxp) > 1024) {
+               ehci_dbg(ehci, "bogus qh maxpacket %d\n", max_packet(maxp));
+               goto done;
+       }
+
        /* Compute interrupt scheduling parameters just once, and save.
         * - allowing for high bandwidth, how many nsec/uframe are used?
         * - split transactions need a second CSPLIT uframe; same question
@@ -757,7 +793,13 @@ qh_make (
                        info2 |= (EHCI_TUNE_MULT_HS << 30);
                } else if (type == PIPE_BULK) {
                        info1 |= (EHCI_TUNE_RL_HS << 28);
-                       info1 |= 512 << 16;     /* usb2 fixed maxpacket */
+                       /* The USB spec says that high speed bulk endpoints
+                        * always use 512 byte maxpacket.  But some device
+                        * vendors decided to ignore that, and MSFT is happy
+                        * to help them do so.  So now people expect to use
+                        * such nonconformant devices with Linux too; sigh.
+                        */
+                       info1 |= max_packet(maxp) << 16;
                        info2 |= (EHCI_TUNE_MULT_HS << 30);
                } else {                /* PIPE_INTERRUPT */
                        info1 |= max_packet (maxp) << 16;
@@ -841,7 +883,7 @@ static struct ehci_qh *qh_append_tds (
 )
 {
        struct ehci_qh          *qh = NULL;
-       u32                     qh_addr_mask = cpu_to_hc32(ehci, 0x7f);
+       __hc32                  qh_addr_mask = cpu_to_hc32(ehci, 0x7f);
 
        qh = (struct ehci_qh *) *ptr;
        if (unlikely (qh == NULL)) {
@@ -932,7 +974,7 @@ submit_async (
 #ifdef EHCI_URB_TRACE
        ehci_dbg (ehci,
                "%s %s urb %p ep%d%s len %d, qtd %p [qh %p]\n",
-               __FUNCTION__, urb->dev->devpath, urb,
+               __func__, urb->dev->devpath, urb,
                epnum & 0x0f, (epnum & USB_DIR_IN) ? "in" : "out",
                urb->transfer_buffer_length,
                qtd, urb->ep->hcpriv);
@@ -1074,8 +1116,7 @@ static void scan_async (struct ehci_hcd *ehci)
        struct ehci_qh          *qh;
        enum ehci_timer_action  action = TIMER_IO_WATCHDOG;
 
-       if (!++(ehci->stamp))
-               ehci->stamp++;
+       ehci->stamp = ehci_readl(ehci, &ehci->regs->frame_index);
        timer_action_done (ehci, TIMER_ASYNC_SHRINK);
 rescan:
        qh = ehci->async->qh_next.qh;
@@ -1100,18 +1141,20 @@ rescan:
                                }
                        }
 
-                       /* unlink idle entries, reducing HC PCI usage as well
+                       /* unlink idle entries, reducing DMA usage as well
                         * as HCD schedule-scanning costs.  delay for any qh
                         * we just scanned, there's a not-unusual case that it
                         * doesn't stay idle for long.
                         * (plus, avoids some kind of re-activation race.)
                         */
-                       if (list_empty (&qh->qtd_list)) {
-                               if (qh->stamp == ehci->stamp)
+                       if (list_empty(&qh->qtd_list)
+                                       && qh->qh_state == QH_STATE_LINKED) {
+                               if (!ehci->reclaim
+                                       && ((ehci->stamp - qh->stamp) & 0x1fff)
+                                               >= (EHCI_SHRINK_FRAMES * 8))
+                                       start_unlink_async(ehci, qh);
+                               else
                                        action = TIMER_ASYNC_SHRINK;
-                               else if (!ehci->reclaim
-                                           && qh->qh_state == QH_STATE_LINKED)
-                                       start_unlink_async (ehci, qh);
                        }
 
                        qh = qh->qh_next.qh;