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[PATCH] UHCI: Remove non-iso TDs as they are used
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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>
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Alan Stern authored and Greg Kroah-Hartman committed Jun 21, 2006
1 parent b186900 commit 59e29ed
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Showing 3 changed files with 45 additions and 39 deletions.
1 change: 1 addition & 0 deletions drivers/usb/host/uhci-debug.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down
5 changes: 2 additions & 3 deletions drivers/usb/host/uhci-hcd.h
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Original file line number Diff line number Diff line change
Expand Up @@ -129,14 +129,15 @@ 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 */
int type; /* Queue type (control, bulk, etc) */

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)));

/*
Expand Down Expand Up @@ -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 */
};


Expand Down
78 changes: 42 additions & 36 deletions drivers/usb/host/uhci-q.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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;
Expand Down Expand Up @@ -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));
}

/*
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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:
Expand Down Expand Up @@ -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;
}

Expand All @@ -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)
Expand Down Expand Up @@ -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;
}
Expand All @@ -882,7 +887,7 @@ static int uhci_result_common(struct uhci_hcd *uhci, struct urb *urb)
(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;
}

Expand Down Expand Up @@ -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,
Expand Down

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