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usb2otg: track periodic-split state for INT/bulk transfers #807

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usb2otg: track periodic-split state for INT/bulk transfers #807

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8 changes: 8 additions & 0 deletions arch/arm-native/soc/broadcom/2708/usb/usb2otg/usb2otg_intern.h
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Original file line number Diff line number Diff line change
Expand Up @@ -197,6 +197,9 @@ struct USB2OTGUnit
UBYTE hc_WatchdogCount; /* Incremented each NakTimeout period while channel active */
UBYTE hc_SplitCSplitPending; /* SSPLIT was issued and request must not be resubmitted yet */
UBYTE hc_DeferCount; /* Consecutive watchdog defers; caps total defer time */
UBYTE hc_CsplitRetry; /* CSPLIT NYET retries this interval; caps to TT result window */
UBYTE hc_SplitState; /* periodic-split SM: USB2OTG_SPLIT_{IDLE,SS,CS} */
UWORD hc_SplitSSUframe; /* HFNUM&0x3fff uframe the SSPLIT was issued in */
struct IOUsbHWReq * hc_DiagReq; /* Last bulk request tracked on this channel */
ULONG hc_DiagStartFrame;
ULONG hc_DiagLastProgressFrame;
Expand Down Expand Up @@ -333,6 +336,11 @@ struct USB2OTGDevice
#define CHAN_INT_LAST CHAN_INT5
#define CHAN_BULK2 7

/* Periodic-split sequencer state (hc_SplitState). */
#define USB2OTG_SPLIT_IDLE 0 /* not a split, or split sequence finished */
#define USB2OTG_SPLIT_SS 1 /* SSPLIT issued, awaiting ACK */
#define USB2OTG_SPLIT_CS 2 /* CSPLIT issued/pending, awaiting completion */

/*
* Bulk-OUT per-packet throttle (busy-wait iterations before arming).
* Some flash devices with tiny SRAM buffers go silent (no NYET/NAK)
Expand Down
66 changes: 64 additions & 2 deletions arch/arm-native/soc/broadcom/2708/usb/usb2otg/usb2otg_intr.c
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Original file line number Diff line number Diff line change
Expand Up @@ -634,13 +634,26 @@ void FNAME_DEV(GlobalIRQHandler)(struct USB2OTGUnit *USBUnit, struct ExecBase *S
tmp |= 1 << 16; /* Set "do complete split" */
wr32le(USB2OTG_CHANNEL_REG(chan, SPLITCTRL), tmp);
USBUnit->hu_Channel[chan].hc_SplitCSplitPending = 1;
/* Fresh CSPLIT sequence — reset the NYET retry window. */
USBUnit->hu_Channel[chan].hc_CsplitRetry = 0;
USBUnit->hu_Channel[chan].hc_SplitState = USB2OTG_SPLIT_CS;

if (req->iouh_Req.io_Command == UHCMD_BULKXFER)
usb2otg_remove_bulk_queue_duplicates(USBUnit, req, chan);

D(bug("[USB2OTG] Completing split transaction in interrupt: chan=%d intr=%04x SPLITCTRL=%08x\n",
chan, intr, tmp));
FNAME_DEV(StartChannel)(USBUnit, chan, 1);

/*
* Periodic INT split: issue the CSPLIT one microframe
* later (delayed_channel[] ticks per SOF) so it lands in
* the TT result window instead of hammering the same
* uframe. Bulk keeps the immediate re-arm.
*/
if (chan >= CHAN_INT1 && chan <= CHAN_INT_LAST)
delayed_channel[chan] = 1;
else
FNAME_DEV(StartChannel)(USBUnit, chan, 1);
}
else if ((do_split == USB2OTG_HCSPLT_CSPLIT) &&
(req->iouh_Req.io_Command == UHCMD_BULKXFER) &&
Expand Down Expand Up @@ -714,7 +727,36 @@ void FNAME_DEV(GlobalIRQHandler)(struct USB2OTGUnit *USBUnit, struct ExecBase *S
else
{
if (chan >= CHAN_INT1 && chan <= CHAN_INT_LAST)
FNAME_DEV(StartChannel)(USBUnit, chan, 1);
{
/*
* CSPLIT NYET = TT has not finished the
* LS/FS transaction yet. Retry the CSPLIT
* one microframe later (delayed_channel
* ticks per SOF = per microframe in HS)
* rather than re-arming in the same uframe.
* Bound to ~8 uframes from the SSPLIT
* (FreeBSD DWC_OTG_TT_SLOT_MAX); past that
* the TT result window is gone, so requeue
* for the next interval.
*/
if (USBUnit->hu_Channel[chan].hc_CsplitRetry < 8)
{
USBUnit->hu_Channel[chan].hc_CsplitRetry++;
delayed_channel[chan] = 1;
}
else
{
ULONG interval = req->iouh_Interval;
usb2otg_halt_channel_preserve_char(chan);
if ((req->iouh_Flags & UHFF_SPLITTRANS) && interval < 2)
interval = 2;
ULONG next = (frnm + interval) & 0x7ff;
req->iouh_DriverPrivate1 = (APTR)((frnm << 16) | next);
ADDHEAD(&USBUnit->hu_IntXFerQueue, req);
USBUnit->hu_Channel[chan].hc_Request = NULL;
req = NULL;
}
}
else
delayed_channel[chan] = 16;
}
Expand Down Expand Up @@ -1676,6 +1718,25 @@ static BOOL usb2otg_process_naktimeout(struct USB2OTGUnit *otg_Unit)
continue;
}

/*
* SOF scheduler owns active periodic-split channels: a CSPLIT
* re-arm is pending within microframes (delayed_channel != 0),
* so the channel is not stuck. Defer — the watchdog's lost-IRQ
* recovery would otherwise race the SS->CS handoff and corrupt
* CompSplt. The sequencer's bounded retry/requeue is the backstop.
*/
if (chan >= CHAN_INT1 && chan <= CHAN_INT_LAST &&
otg_Unit->hu_Channel[chan].hc_SplitState != USB2OTG_SPLIT_IDLE &&
delayed_channel[chan] != 0)
{
#if defined(__AROSEXEC_SMP__)
KrnSpinUnLock(&otg_Unit->hu_Lock);
#endif
Enable();
otg_Unit->hu_Channel[chan].hc_WatchdogCount = 0;
continue;
}

ULONG charbase = rd32le(USB2OTG_CHANNEL_REG(chan, CHARBASE));

if (!(charbase & USB2OTG_HOSTCHAR_ENABLE))
Expand Down Expand Up @@ -2061,6 +2122,7 @@ static BOOL usb2otg_process_naktimeout(struct USB2OTGUnit *otg_Unit)
{
otg_Unit->hu_Channel[chan].hc_DeferCount++;
otg_Unit->hu_Channel[chan].hc_WatchdogCount = 0;

D(
{
struct USB2OTGChannel *hc = &otg_Unit->hu_Channel[chan];
Expand Down
32 changes: 30 additions & 2 deletions arch/arm-native/soc/broadcom/2708/usb/usb2otg/usb2otg_schedule.c
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Original file line number Diff line number Diff line change
Expand Up @@ -318,6 +318,17 @@ BOOL FNAME_DEV(SetupChannel)(struct USB2OTGUnit *otg_Unit, int chan)

/* Fresh request: clear watchdog defer counter. */
otg_Unit->hu_Channel[chan].hc_DeferCount = 0;
otg_Unit->hu_Channel[chan].hc_CsplitRetry = 0;

/*
* A fresh arm is always a START-split — clear any CSPLIT-pending left
* over from a prior interval that requeued mid-split. If it leaks set,
* the splitpos logic below picks XactPos=0 (CSPLIT) instead of ALL,
* producing a malformed periodic SSPLIT that halts with bare CHHLTD.
* CSPLIT is only ever armed via StartChannel(quick=1) from the IRQ.
*/
otg_Unit->hu_Channel[chan].hc_SplitCSplitPending = 0;
otg_Unit->hu_Channel[chan].hc_SplitState = USB2OTG_SPLIT_IDLE;

/*
* Inherit PING state from per-EP bitmap (channel-local flag does
Expand Down Expand Up @@ -464,8 +475,13 @@ BOOL FNAME_DEV(SetupChannel)(struct USB2OTGUnit *otg_Unit, int chan)
/* If split transaction requested limit transfer size to max packet size or 188 bytes, whichever is less */
if (req->iouh_Flags & UHFF_SPLITTRANS)
{
if (req->iouh_Req.io_Command == UHCMD_INTXFER ||
req->iouh_Req.io_Command == UHCMD_ISOXFER)
/*
* HCCHAR.EC/MC = transactions per microframe; only high-bandwidth
* HS endpoints use >1. A low-/full-speed INT split must be EC=1
* (matches Linux dwc2 multi_count=1) — EC=3 makes the core expect
* 3 transactions and deschedule the periodic split (bare CHHLTD).
*/
if (req->iouh_Req.io_Command == UHCMD_ISOXFER)
reg |= USB2OTG_HOSTCHAR_EC(3);
else
reg |= USB2OTG_HOSTCHAR_EC(1);
Expand All @@ -492,6 +508,18 @@ BOOL FNAME_DEV(SetupChannel)(struct USB2OTGUnit *otg_Unit, int chan)
((req->iouh_SplitHubPort & 0x0f)));
}

/*
* Periodic-split sequencer: a fresh INT split arm is a START-split.
* Record the phase and the microframe it is issued in so the SS->CS
* handoff can be paced and the watchdog can defer to this scheduler.
*/
if (req->iouh_Req.io_Command == UHCMD_INTXFER)
{
otg_Unit->hu_Channel[chan].hc_SplitState = USB2OTG_SPLIT_SS;
otg_Unit->hu_Channel[chan].hc_SplitSSUframe =
(UWORD)(rd32le(USB2OTG_HOSTFRAMENO) & 0x3fff);
}

if (xfer_size > req->iouh_MaxPktSize)
xfer_size = req->iouh_MaxPktSize;

Expand Down