ChangeSet 1.1290.15.7, 2004/02/05 16:34:05-08:00, [EMAIL PROTECTED]
[PATCH] USB: EHCI updates (mostly periodic schedule scanning)
[USB] EHCI updates
Update periodic schedule scanning
- fix shutdown sometimes-hangs (Bernd Porr)
- resolve the "whole frame at once" FIXME
- try harder to avoid rescanning
- don't delegate interrupt qh handling to a buggy helper routine
- describe more of the relevant iso tuning parameters
One-liners:
- URB_NO_INTERRUPT hint affects ISO
- show correct data toggle in sysfs debug files
- FIXME is resolved by Linus' 20msec delay
drivers/usb/host/ehci-dbg.c | 2
drivers/usb/host/ehci-hub.c | 2
drivers/usb/host/ehci-sched.c | 96 ++++++++++++++----------------------------
3 files changed, 34 insertions(+), 66 deletions(-)
diff -Nru a/drivers/usb/host/ehci-dbg.c b/drivers/usb/host/ehci-dbg.c
--- a/drivers/usb/host/ehci-dbg.c Wed Mar 17 15:48:54 2004
+++ b/drivers/usb/host/ehci-dbg.c Wed Mar 17 15:48:54 2004
@@ -377,7 +377,7 @@
scratch, cpu_to_le32p (&qh->hw_info2),
cpu_to_le32p (&qh->hw_token), mark,
(__constant_cpu_to_le32 (QTD_TOGGLE) & qh->hw_token)
- ? "data0" : "data1",
+ ? "data1" : "data0",
(cpu_to_le32p (&qh->hw_alt_next) >> 1) & 0x0f);
size -= temp;
next += temp;
diff -Nru a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
--- a/drivers/usb/host/ehci-hub.c Wed Mar 17 15:48:54 2004
+++ b/drivers/usb/host/ehci-hub.c Wed Mar 17 15:48:54 2004
@@ -113,7 +113,7 @@
u16 temp;
desc->bDescriptorType = 0x29;
- desc->bPwrOn2PwrGood = 0; /* FIXME: f(system power) */
+ desc->bPwrOn2PwrGood = 10; /* ehci 1.0, 2.3.9 says 20ms max */
desc->bHubContrCurrent = 0;
desc->bNbrPorts = ports;
diff -Nru a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
--- a/drivers/usb/host/ehci-sched.c Wed Mar 17 15:48:54 2004
+++ b/drivers/usb/host/ehci-sched.c Wed Mar 17 15:48:54 2004
@@ -490,33 +490,6 @@
return status;
}
-static unsigned
-intr_complete (
- struct ehci_hcd *ehci,
- unsigned frame,
- struct ehci_qh *qh,
- struct pt_regs *regs
-) {
- unsigned count;
-
- /* nothing to report? */
- if (likely ((qh->hw_token & __constant_cpu_to_le32 (QTD_STS_ACTIVE))
- != 0))
- return 0;
- if (unlikely (list_empty (&qh->qtd_list))) {
- dbg ("intr qh %p no TDs?", qh);
- return 0;
- }
-
- /* handle any completions */
- count = qh_completions (ehci, qh, regs);
-
- if (unlikely (list_empty (&qh->qtd_list)))
- intr_deschedule (ehci, qh, 0);
-
- return count;
-}
-
/*-------------------------------------------------------------------------*/
static inline struct ehci_iso_stream *
@@ -718,7 +691,8 @@
trans = EHCI_ISOC_ACTIVE;
trans |= buf & 0x0fff;
- if (unlikely ((i + 1) == urb->number_of_packets))
+ if (unlikely (((i + 1) == urb->number_of_packets))
+ && !(urb->transfer_flags & URB_NO_INTERRUPT))
trans |= EHCI_ITD_IOC;
trans |= length << 16;
uframe->transaction = cpu_to_le32 (trans);
@@ -809,7 +783,10 @@
* periodic schedule slots. (Affected by TUNE_FLS, which defaults to
* "as small as possible" to be cache-friendlier.) That limits the size
* transfers you can stream reliably; avoid more than 64 msec per urb.
- * Also avoid queue depths of less than the system's worst irq latency.
+ * Also avoid queue depths of less than ehci's worst irq latency (affected
+ * by the per-urb URB_NO_INTERRUPT hint, the log2_irq_thresh module parameter,
+ * and other factors); or more than about 230 msec total (for portability,
+ * given EHCI_TUNE_FLS and the slop). Or, write a smarter scheduler!
*/
#define SCHEDULE_SLOP 10 /* frames */
@@ -1236,7 +1213,7 @@
scan_periodic (struct ehci_hcd *ehci, struct pt_regs *regs)
{
unsigned frame, clock, now_uframe, mod;
- unsigned count = 0;
+ unsigned modified;
mod = ehci->periodic_size << 3;
@@ -1247,47 +1224,50 @@
*/
now_uframe = ehci->next_uframe;
if (HCD_IS_RUNNING (ehci->hcd.state))
- clock = readl (&ehci->regs->frame_index) % mod;
+ clock = readl (&ehci->regs->frame_index);
else
clock = now_uframe + mod - 1;
+ clock %= mod;
for (;;) {
union ehci_shadow q, *q_p;
u32 type, *hw_p;
unsigned uframes;
+ /* don't scan past the live uframe */
frame = now_uframe >> 3;
-restart:
- /* scan schedule to _before_ current frame index */
- if ((frame == (clock >> 3))
- && HCD_IS_RUNNING (ehci->hcd.state))
+ if (frame == (clock >> 3))
uframes = now_uframe & 0x07;
- else
+ else {
+ /* safe to scan the whole frame at once */
+ now_uframe |= 0x07;
uframes = 8;
+ }
+restart:
+ /* scan each element in frame's queue for completions */
q_p = &ehci->pshadow [frame];
hw_p = &ehci->periodic [frame];
q.ptr = q_p->ptr;
type = Q_NEXT_TYPE (*hw_p);
+ modified = 0;
- /* scan each element in frame's queue for completions */
while (q.ptr != 0) {
- int last;
unsigned uf;
union ehci_shadow temp;
switch (type) {
case Q_TYPE_QH:
- last = (q.qh->hw_next == EHCI_LIST_END);
- temp = q.qh->qh_next;
+ /* handle any completions */
+ temp.qh = qh_get (q.qh);
type = Q_NEXT_TYPE (q.qh->hw_next);
- count += intr_complete (ehci, frame,
- qh_get (q.qh), regs);
- qh_put (ehci, q.qh);
- q = temp;
+ q = q.qh->qh_next;
+ modified = qh_completions (ehci, temp.qh, regs);
+ if (unlikely (list_empty (&temp.qh->qtd_list)))
+ intr_deschedule (ehci, temp.qh, 0);
+ qh_put (ehci, temp.qh);
break;
case Q_TYPE_FSTN:
- last = (q.fstn->hw_next == EHCI_LIST_END);
/* for "save place" FSTNs, look at QH entries
* in the previous frame for completions.
*/
@@ -1298,8 +1278,6 @@
q = q.fstn->fstn_next;
break;
case Q_TYPE_ITD:
- last = (q.itd->hw_next == EHCI_LIST_END);
-
/* skip itds for later in the frame */
rmb ();
for (uf = uframes; uf < 8; uf++) {
@@ -1320,31 +1298,24 @@
*/
*q_p = q.itd->itd_next;
*hw_p = q.itd->hw_next;
+ type = Q_NEXT_TYPE (q.itd->hw_next);
wmb();
-
- /* always rescan here; simpler */
- count += itd_complete (ehci, q.itd, regs);
- goto restart;
+ modified = itd_complete (ehci, q.itd, regs);
+ q = *q_p;
+ break;
#ifdef have_split_iso
case Q_TYPE_SITD:
- last = (q.sitd->hw_next == EHCI_LIST_END);
- sitd_complete (ehci, q.sitd);
- type = Q_NEXT_TYPE (q.sitd->hw_next);
-
- // FIXME unlink SITD after split completes
- q = q.sitd->sitd_next;
- break;
+ // nyet!
#endif /* have_split_iso */
default:
dbg ("corrupt type %d frame %d shadow %p",
type, frame, q.ptr);
// BUG ();
- last = 1;
q.ptr = 0;
}
- /* did completion remove an interior q entry? */
- if (unlikely (q.ptr == 0 && !last))
+ /* assume completion callbacks modify the queue */
+ if (unlikely (modified))
goto restart;
}
@@ -1371,9 +1342,6 @@
/* rescan the rest of this frame, then ... */
clock = now;
} else {
- /* FIXME sometimes we can scan the next frame
- * right away, not always inching up on it ...
- */
now_uframe++;
now_uframe %= mod;
}
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