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path: root/drivers/usb/host/ehci-sched.c
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Diffstat (limited to 'drivers/usb/host/ehci-sched.c')
-rw-r--r--drivers/usb/host/ehci-sched.c136
1 files changed, 61 insertions, 75 deletions
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 7cf3da7babf..69ebee73c0c 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -36,29 +36,6 @@
static int ehci_get_frame (struct usb_hcd *hcd);
-#ifdef CONFIG_PCI
-
-static unsigned ehci_read_frame_index(struct ehci_hcd *ehci)
-{
- unsigned uf;
-
- /*
- * The MosChip MCS9990 controller updates its microframe counter
- * a little before the frame counter, and occasionally we will read
- * the invalid intermediate value. Avoid problems by checking the
- * microframe number (the low-order 3 bits); if they are 0 then
- * re-read the register to get the correct value.
- */
- uf = ehci_readl(ehci, &ehci->regs->frame_index);
- if (unlikely(ehci->frame_index_bug && ((uf & 7) == 0)))
- uf = ehci_readl(ehci, &ehci->regs->frame_index);
- return uf;
-}
-
-#endif
-
-/*-------------------------------------------------------------------------*/
-
/*
* periodic_next_shadow - return "next" pointer on shadow list
* @periodic: host pointer to qh/itd/sitd
@@ -1361,7 +1338,7 @@ sitd_slot_ok (
* given EHCI_TUNE_FLS and the slop). Or, write a smarter scheduler!
*/
-#define SCHEDULE_SLOP 80 /* microframes */
+#define SCHEDULING_DELAY 40 /* microframes */
static int
iso_stream_schedule (
@@ -1370,7 +1347,7 @@ iso_stream_schedule (
struct ehci_iso_stream *stream
)
{
- u32 now, next, start, period, span;
+ u32 now, base, next, start, period, span;
int status;
unsigned mod = ehci->periodic_size << 3;
struct ehci_iso_sched *sched = urb->hcpriv;
@@ -1382,62 +1359,72 @@ iso_stream_schedule (
span <<= 3;
}
- if (span > mod - SCHEDULE_SLOP) {
- ehci_dbg (ehci, "iso request %p too long\n", urb);
- status = -EFBIG;
- goto fail;
- }
-
now = ehci_read_frame_index(ehci) & (mod - 1);
/* 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.
+ * (irq delays etc). If there are, the behavior depends on
+ * whether URB_ISO_ASAP is set.
*/
if (likely (!list_empty (&stream->td_list))) {
- u32 excess;
- /* For high speed devices, allow scheduling within the
- * isochronous scheduling threshold. For full speed devices
- * and Intel PCI-based controllers, don't (work around for
- * Intel ICH9 bug).
- */
- if (!stream->highspeed && ehci->fs_i_thresh)
- next = now + ehci->i_thresh;
+ /* Take the isochronous scheduling threshold into account */
+ if (ehci->i_thresh)
+ next = now + ehci->i_thresh; /* uframe cache */
else
- next = now;
+ next = (now + 2 + 7) & ~0x07; /* full frame cache */
- /* Fell behind (by up to twice the slop amount)?
- * We decide based on the time of the last currently-scheduled
- * slot, not the time of the next available slot.
+ /*
+ * Use ehci->last_iso_frame as the base. There can't be any
+ * TDs scheduled for earlier than that.
*/
- excess = (stream->next_uframe - period - next) & (mod - 1);
- if (excess >= mod - 2 * SCHEDULE_SLOP)
- start = next + excess - mod + period *
- DIV_ROUND_UP(mod - excess, period);
- else
- start = next + excess + period;
- if (start - now >= mod) {
- ehci_dbg(ehci, "request %p would overflow (%d+%d >= %d)\n",
- urb, start - now - period, period,
- mod);
- status = -EFBIG;
+ base = ehci->last_iso_frame << 3;
+ next = (next - base) & (mod - 1);
+ start = (stream->next_uframe - base) & (mod - 1);
+
+ /* Is the schedule already full? */
+ if (unlikely(start < period)) {
+ ehci_dbg(ehci, "iso sched full %p (%u-%u < %u mod %u)\n",
+ urb, stream->next_uframe, base,
+ period, mod);
+ status = -ENOSPC;
goto fail;
}
+
+ /* Behind the scheduling threshold? */
+ if (unlikely(start < next)) {
+
+ /* USB_ISO_ASAP: Round up to the first available slot */
+ if (urb->transfer_flags & URB_ISO_ASAP)
+ start += (next - start + period - 1) & -period;
+
+ /*
+ * Not ASAP: Use the next slot in the stream. If
+ * the entire URB falls before the threshold, fail.
+ */
+ else if (start + span - period < next) {
+ ehci_dbg(ehci, "iso urb late %p (%u+%u < %u)\n",
+ urb, start + base,
+ span - period, next + base);
+ status = -EXDEV;
+ goto fail;
+ }
+ }
+
+ start += base;
}
/* need to schedule; when's the next (u)frame we could start?
* this is bigger than ehci->i_thresh allows; scheduling itself
- * isn't free, the slop should handle reasonably slow cpus. it
+ * isn't free, the delay should handle reasonably slow cpus. it
* can also help high bandwidth if the dma and irq loads don't
* jump until after the queue is primed.
*/
else {
int done = 0;
- start = SCHEDULE_SLOP + (now & ~0x07);
- /* NOTE: assumes URB_ISO_ASAP, to limit complexity/bugs */
+ base = now & ~0x07;
+ start = base + SCHEDULING_DELAY;
/* find a uframe slot with enough bandwidth.
* Early uframes are more precious because full-speed
@@ -1464,19 +1451,16 @@ iso_stream_schedule (
/* no room in the schedule */
if (!done) {
- ehci_dbg(ehci, "iso resched full %p (now %d max %d)\n",
- urb, now, now + mod);
+ ehci_dbg(ehci, "iso sched full %p", urb);
status = -ENOSPC;
goto fail;
}
}
/* Tried to schedule too far into the future? */
- if (unlikely(start - now + span - period
- >= mod - 2 * SCHEDULE_SLOP)) {
- ehci_dbg(ehci, "request %p would overflow (%d+%d >= %d)\n",
- urb, start - now, span - period,
- mod - 2 * SCHEDULE_SLOP);
+ if (unlikely(start - base + span - period >= mod)) {
+ ehci_dbg(ehci, "request %p would overflow (%u+%u >= %u)\n",
+ urb, start - base, span - period, mod);
status = -EFBIG;
goto fail;
}
@@ -1490,7 +1474,7 @@ iso_stream_schedule (
/* Make sure scan_isoc() sees these */
if (ehci->isoc_count == 0)
- ehci->next_frame = now >> 3;
+ ehci->last_iso_frame = now >> 3;
return 0;
fail:
@@ -1646,7 +1630,7 @@ static void itd_link_urb(
/* don't need that schedule data any more */
iso_sched_free (stream, iso_sched);
- urb->hcpriv = NULL;
+ urb->hcpriv = stream;
++ehci->isoc_count;
enable_periodic(ehci);
@@ -1708,7 +1692,7 @@ static bool itd_complete(struct ehci_hcd *ehci, struct ehci_itd *itd)
urb->actual_length += desc->actual_length;
} else {
/* URB was too late */
- desc->status = -EXDEV;
+ urb->error_count++;
}
}
@@ -2045,7 +2029,7 @@ static void sitd_link_urb(
/* don't need that schedule data any more */
iso_sched_free (stream, sched);
- urb->hcpriv = NULL;
+ urb->hcpriv = stream;
++ehci->isoc_count;
enable_periodic(ehci);
@@ -2081,7 +2065,7 @@ static bool sitd_complete(struct ehci_hcd *ehci, struct ehci_sitd *sitd)
t = hc32_to_cpup(ehci, &sitd->hw_results);
/* report transfer status */
- if (t & SITD_ERRS) {
+ if (unlikely(t & SITD_ERRS)) {
urb->error_count++;
if (t & SITD_STS_DBE)
desc->status = usb_pipein (urb->pipe)
@@ -2091,6 +2075,9 @@ static bool sitd_complete(struct ehci_hcd *ehci, struct ehci_sitd *sitd)
desc->status = -EOVERFLOW;
else /* XACT, MMF, etc */
desc->status = -EPROTO;
+ } else if (unlikely(t & SITD_STS_ACTIVE)) {
+ /* URB was too late */
+ urb->error_count++;
} else {
desc->status = 0;
desc->actual_length = desc->length - SITD_LENGTH(t);
@@ -2220,16 +2207,16 @@ static void scan_isoc(struct ehci_hcd *ehci)
now_frame = (uf >> 3) & fmask;
live = true;
} else {
- now_frame = (ehci->next_frame - 1) & fmask;
+ now_frame = (ehci->last_iso_frame - 1) & fmask;
live = false;
}
ehci->now_frame = now_frame;
- frame = ehci->next_frame;
for (;;) {
union ehci_shadow q, *q_p;
__hc32 type, *hw_p;
+ frame = ehci->last_iso_frame;
restart:
/* scan each element in frame's queue for completions */
q_p = &ehci->pshadow [frame];
@@ -2334,7 +2321,6 @@ restart:
/* Stop when we have reached the current frame */
if (frame == now_frame)
break;
- frame = (frame + 1) & fmask;
+ ehci->last_iso_frame = (frame + 1) & fmask;
}
- ehci->next_frame = now_frame;
}
generated by cgit v1.2.3-70-g09d2 (git 2.51.2) at 2025-11-04 13:08:05 +0000