[PATCH] UHCI: Remove non-iso TDs as they are used

This patch (as680) frees non-isochronous TDs as they are used, rather
than all at once when an URB is complete.  Although not a terribly
important change in itself, it opens the door to a later enhancement
that will reduce storage requirements by allocating only a limited
number of TDs at any time for each endpoint queue.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/host/uhci-debug.c b/drivers/usb/host/uhci-debug.c
index 28c1c51ec475b43fcbeceae0480e07a0cf32232d..6bbd33db9358322c77c03ec99039bd709088da57 100644 (file)
--- a/drivers/usb/host/uhci-debug.c
+++ b/drivers/usb/host/uhci-debug.c
@@ -119,6 +119,7 @@ static int uhci_show_urbp(struct urb_priv *urbp, char *buf, int len, int space)
        }
 
        out += sprintf(out, "%s%s", ptype, (urbp->fsbr ? " FSBR" : ""));
+       out += sprintf(out, " Actlen=%d", urbp->urb->actual_length);
 
        if (urbp->urb->status != -EINPROGRESS)
                out += sprintf(out, " Status=%d", urbp->urb->status);

diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
index 8e5778650493fd06c28a43b9af00e2fe3e355517..3093ca25094284a4872f5d34c8b355aa62360611 100644 (file)
--- a/drivers/usb/host/uhci-hcd.h
+++ b/drivers/usb/host/uhci-hcd.h
@@ -129,6 +129,7 @@ struct uhci_qh {
        struct list_head queue;         /* Queue of urbps for this QH */
        struct uhci_qh *skel;           /* Skeleton for this QH */
        struct uhci_td *dummy_td;       /* Dummy TD to end the queue */
+       struct uhci_td *post_td;        /* Last TD completed */
 
        unsigned int unlink_frame;      /* When the QH was unlinked */
        int state;                      /* QH_STATE_xxx; see above */
@@ -136,7 +137,7 @@ struct uhci_qh {
 
        unsigned int initial_toggle:1;  /* Endpoint's current toggle value */
        unsigned int needs_fixup:1;     /* Must fix the TD toggle values */
-       unsigned int is_stopped:1;      /* Queue was stopped by an error */
+       unsigned int is_stopped:1;      /* Queue was stopped by error/unlink */
 } __attribute__((aligned(16)));
 
 /*
@@ -456,8 +457,6 @@ struct urb_priv {
        struct list_head td_list;
 
        unsigned fsbr : 1;              /* URB turned on FSBR */
-       unsigned short_transfer : 1;    /* URB got a short transfer, no
-                                        * need to rescan */
 };
 
 

diff --git a/drivers/usb/host/uhci-q.c b/drivers/usb/host/uhci-q.c
index 30e36031fe212fd9719b937cff088b862eb56138..888938d78230ba6c92197a1f32640fb4451bb5fa 100644 (file)
--- a/drivers/usb/host/uhci-q.c
+++ b/drivers/usb/host/uhci-q.c
@@ -161,6 +161,7 @@ static struct uhci_qh *uhci_alloc_qh(struct uhci_hcd *uhci,
        if (!qh)
                return NULL;
 
+       memset(qh, 0, sizeof(*qh));
        qh->dma_handle = dma_handle;
 
        qh->element = UHCI_PTR_TERM;
@@ -183,7 +184,6 @@ static struct uhci_qh *uhci_alloc_qh(struct uhci_hcd *uhci,
 
        } else {                /* Skeleton QH */
                qh->state = QH_STATE_ACTIVE;
-               qh->udev = NULL;
                qh->type = -1;
        }
        return qh;
@@ -223,16 +223,10 @@ static void uhci_save_toggle(struct uhci_qh *qh, struct urb *urb)
                        qh->type == USB_ENDPOINT_XFER_INT))
                return;
 
-       /* Find the first active TD; that's the device's toggle state */
-       list_for_each_entry(td, &urbp->td_list, list) {
-               if (td_status(td) & TD_CTRL_ACTIVE) {
-                       qh->needs_fixup = 1;
-                       qh->initial_toggle = uhci_toggle(td_token(td));
-                       return;
-               }
-       }
-
-       WARN_ON(1);
+       WARN_ON(list_empty(&urbp->td_list));
+       td = list_entry(urbp->td_list.next, struct uhci_td, list);
+       qh->needs_fixup = 1;
+       qh->initial_toggle = uhci_toggle(td_token(td));
 }
 
 /*
@@ -372,6 +366,12 @@ static void uhci_make_qh_idle(struct uhci_hcd *uhci, struct uhci_qh *qh)
        list_move(&qh->node, &uhci->idle_qh_list);
        qh->state = QH_STATE_IDLE;
 
+       /* Now that the QH is idle, its post_td isn't being used */
+       if (qh->post_td) {
+               uhci_free_td(uhci, qh->post_td);
+               qh->post_td = NULL;
+       }
+
        /* If anyone is waiting for a QH to become idle, wake them up */
        if (uhci->num_waiting)
                wake_up_all(&uhci->waitqh);
@@ -610,6 +610,8 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb,
                qh->skel = uhci->skel_fs_control_qh;
                uhci_inc_fsbr(uhci, urb);
        }
+
+       urb->actual_length = -8;        /* Account for the SETUP packet */
        return 0;
 
 nomem:
@@ -767,34 +769,46 @@ static inline int uhci_submit_interrupt(struct uhci_hcd *uhci, struct urb *urb,
  * Fix up the data structures following a short transfer
  */
 static int uhci_fixup_short_transfer(struct uhci_hcd *uhci,
-               struct uhci_qh *qh, struct urb_priv *urbp,
-               struct uhci_td *short_td)
+               struct uhci_qh *qh, struct urb_priv *urbp)
 {
        struct uhci_td *td;
-       int ret = 0;
+       struct list_head *tmp;
+       int ret;
 
        td = list_entry(urbp->td_list.prev, struct uhci_td, list);
        if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
-               urbp->short_transfer = 1;
 
                /* When a control transfer is short, we have to restart
                 * the queue at the status stage transaction, which is
                 * the last TD. */
+               WARN_ON(list_empty(&urbp->td_list));
                qh->element = cpu_to_le32(td->dma_handle);
+               tmp = td->list.prev;
                ret = -EINPROGRESS;
 
-       } else if (!urbp->short_transfer) {
-               urbp->short_transfer = 1;
+       } else {
 
                /* When a bulk/interrupt transfer is short, we have to
                 * fix up the toggles of the following URBs on the queue
                 * before restarting the queue at the next URB. */
-               qh->initial_toggle = uhci_toggle(td_token(short_td)) ^ 1;
+               qh->initial_toggle = uhci_toggle(td_token(qh->post_td)) ^ 1;
                uhci_fixup_toggles(qh, 1);
 
+               if (list_empty(&urbp->td_list))
+                       td = qh->post_td;
                qh->element = td->link;
+               tmp = urbp->td_list.prev;
+               ret = 0;
        }
 
+       /* Remove all the TDs we skipped over, from tmp back to the start */
+       while (tmp != &urbp->td_list) {
+               td = list_entry(tmp, struct uhci_td, list);
+               tmp = tmp->prev;
+
+               uhci_remove_td_from_urb(td);
+               list_add(&td->remove_list, &uhci->td_remove_list);
+       }
        return ret;
 }
 
@@ -805,29 +819,14 @@ static int uhci_result_common(struct uhci_hcd *uhci, struct urb *urb)
 {
        struct urb_priv *urbp = urb->hcpriv;
        struct uhci_qh *qh = urbp->qh;
-       struct uhci_td *td;
-       struct list_head *tmp;
+       struct uhci_td *td, *tmp;
        unsigned status;
        int ret = 0;
 
-       tmp = urbp->td_list.next;
-
-       if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
-               if (urbp->short_transfer)
-                       tmp = urbp->td_list.prev;
-               else
-                       urb->actual_length = -8;        /* SETUP packet */
-       } else
-               urb->actual_length = 0;
-
-
-       while (tmp != &urbp->td_list) {
+       list_for_each_entry_safe(td, tmp, &urbp->td_list, list) {
                unsigned int ctrlstat;
                int len;
 
-               td = list_entry(tmp, struct uhci_td, list);
-               tmp = tmp->next;
-
                ctrlstat = td_status(td);
                status = uhci_status_bits(ctrlstat);
                if (status & TD_CTRL_ACTIVE)
@@ -862,6 +861,12 @@ static int uhci_result_common(struct uhci_hcd *uhci, struct urb *urb)
                                ret = 1;
                }
 
+               uhci_remove_td_from_urb(td);
+               if (qh->post_td)
+                       list_add(&qh->post_td->remove_list,
+                                       &uhci->td_remove_list);
+               qh->post_td = td;
+
                if (ret != 0)
                        goto err;
        }
@@ -882,7 +887,7 @@ err:
                                (ret == -EREMOTEIO);
 
        } else          /* Short packet received */
-               ret = uhci_fixup_short_transfer(uhci, qh, urbp, td);
+               ret = uhci_fixup_short_transfer(uhci, qh, urbp);
        return ret;
 }
 
@@ -1123,6 +1128,7 @@ __acquires(uhci->lock)
                struct uhci_td *ptd, *ltd;
 
                purbp = list_entry(urbp->node.prev, struct urb_priv, node);
+               WARN_ON(list_empty(&purbp->td_list));
                ptd = list_entry(purbp->td_list.prev, struct uhci_td,
                                list);
                ltd = list_entry(urbp->td_list.prev, struct uhci_td,