USB: OHCI handles more ZFMicro quirks

The ZF Micro OHCI controller exhibits unexpected behavior that seems to be
related to high load.  Under certain conditions, the controller will
complete a TD, remove it from the endpoint's queue, and fail to add it to
the donelist. This causes the endpoint to appear to stop responding. Worse,
if the device is removed while in that state, OHCI will hang while waiting
for the orphaned TD to complete.  The situation is not recoverable without
rebooting.

This fix enhances the scope of the existing OHCI_QUIRK_ZFMICRO flag:

 1. A watchdog routine periodically scans the OHCI structures to check
    for orphaned TDs. In these cases the TD is taken back from the
    controller and completed normally.

 2. If a device is removed while the endpoint is hung but before the
    watchdog catches the situation, any outstanding TDs are taken back
    from the controller in the 'sanitize' phase.

The ohci-hcd driver used to print "INTR_SF lossage" in this situation;
this changes it to the universally accurate "ED unlink timeout".  Other
instances of this message presumably have different root causes.

Both this Compaq quirk and a NEC quirk are now properly compiled out for
non-PCI builds of this driver.

Signed-off-by: Mike Nuss <mike@terascala.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 67 insertions, 46 deletions

diff --git a/drivers/usb/host/ohci-q.c b/drivers/usb/host/ohci-q.c
index 830a3fe8615..547d39be3eb 100644
--- a/drivers/usb/host/ohci-q.c
+++ b/drivers/usb/host/ohci-q.c
@@ -179,6 +179,10 @@ static int ed_schedule (struct ohci_hcd *ohci, struct ed *ed)
 	ed->ed_prev = NULL;
 	ed->ed_next = NULL;
 	ed->hwNextED = 0;
+	if (quirk_zfmicro(ohci)
+			&& (ed->type == PIPE_INTERRUPT)
+			&& !(ohci->eds_scheduled++))
+		mod_timer(&ohci->unlink_watchdog, round_jiffies_relative(HZ));
 	wmb ();
 
 	/* we care about rm_list when setting CLE/BLE in case the HC was at
@@ -940,8 +944,12 @@ skip_ed:
 								TD_MASK;
 
 				/* INTR_WDH may need to clean up first */
-				if (td->td_dma != head)
-					goto skip_ed;
+				if (td->td_dma != head) {
+					if (ed == ohci->ed_to_check)
+						ohci->ed_to_check = NULL;
+					else
+						goto skip_ed;
+				}
 			}
 		}
 
@@ -998,6 +1006,8 @@ rescan_this:
 
 		/* ED's now officially unlinked, hc doesn't see */
 		ed->state = ED_IDLE;
+		if (quirk_zfmicro(ohci) && ed->type == PIPE_INTERRUPT)
+			ohci->eds_scheduled--;
 		ed->hwHeadP &= ~cpu_to_hc32(ohci, ED_H);
 		ed->hwNextED = 0;
 		wmb ();
@@ -1021,7 +1031,7 @@ rescan_this:
 
 		if (ohci->ed_controltail) {
 			command |= OHCI_CLF;
-			if (ohci->flags & OHCI_QUIRK_ZFMICRO)
+			if (quirk_zfmicro(ohci))
 				mdelay(1);
 			if (!(ohci->hc_control & OHCI_CTRL_CLE)) {
 				control |= OHCI_CTRL_CLE;
@@ -1031,7 +1041,7 @@ rescan_this:
 		}
 		if (ohci->ed_bulktail) {
 			command |= OHCI_BLF;
-			if (ohci->flags & OHCI_QUIRK_ZFMICRO)
+			if (quirk_zfmicro(ohci))
 				mdelay(1);
 			if (!(ohci->hc_control & OHCI_CTRL_BLE)) {
 				control |= OHCI_CTRL_BLE;
@@ -1043,13 +1053,13 @@ rescan_this:
 		/* CLE/BLE to enable, CLF/BLF to (maybe) kickstart */
 		if (control) {
 			ohci->hc_control |= control;
-			if (ohci->flags & OHCI_QUIRK_ZFMICRO)
+			if (quirk_zfmicro(ohci))
 				mdelay(1);
 			ohci_writel (ohci, ohci->hc_control,
 					&ohci->regs->control);
 		}
 		if (command) {
-			if (ohci->flags & OHCI_QUIRK_ZFMICRO)
+			if (quirk_zfmicro(ohci))
 				mdelay(1);
 			ohci_writel (ohci, command, &ohci->regs->cmdstatus);
 		}
@@ -1061,11 +1071,59 @@ rescan_this:
 /*-------------------------------------------------------------------------*/
 
 /*
+ * Used to take back a TD from the host controller. This would normally be
+ * called from within dl_done_list, however it may be called directly if the
+ * HC no longer sees the TD and it has not appeared on the donelist (after
+ * two frames).  This bug has been observed on ZF Micro systems.
+ */
+static void takeback_td(struct ohci_hcd *ohci, struct td *td)
+{
+	struct urb	*urb = td->urb;
+	urb_priv_t	*urb_priv = urb->hcpriv;
+	struct ed	*ed = td->ed;
+
+	/* update URB's length and status from TD */
+	td_done(ohci, urb, td);
+	urb_priv->td_cnt++;
+
+	/* If all this urb's TDs are done, call complete() */
+	if (urb_priv->td_cnt == urb_priv->length)
+		finish_urb(ohci, urb);
+
+	/* clean schedule:  unlink EDs that are no longer busy */
+	if (list_empty(&ed->td_list)) {
+		if (ed->state == ED_OPER)
+			start_ed_unlink(ohci, ed);
+
+	/* ... reenabling halted EDs only after fault cleanup */
+	} else if ((ed->hwINFO & cpu_to_hc32(ohci, ED_SKIP | ED_DEQUEUE))
+			== cpu_to_hc32(ohci, ED_SKIP)) {
+		td = list_entry(ed->td_list.next, struct td, td_list);
+		if (!(td->hwINFO & cpu_to_hc32(ohci, TD_DONE))) {
+			ed->hwINFO &= ~cpu_to_hc32(ohci, ED_SKIP);
+			/* ... hc may need waking-up */
+			switch (ed->type) {
+			case PIPE_CONTROL:
+				ohci_writel(ohci, OHCI_CLF,
+						&ohci->regs->cmdstatus);
+				break;
+			case PIPE_BULK:
+				ohci_writel(ohci, OHCI_BLF,
+						&ohci->regs->cmdstatus);
+				break;
+			}
+		}
+	}
+}
+
+/*
  * Process normal completions (error or success) and clean the schedules.
  *
  * This is the main path for handing urbs back to drivers.  The only other
- * path is finish_unlinks(), which unlinks URBs using ed_rm_list, instead of
- * scanning the (re-reversed) donelist as this does.
+ * normal path is finish_unlinks(), which unlinks URBs using ed_rm_list,
+ * instead of scanning the (re-reversed) donelist as this does.  There's
+ * an abnormal path too, handling a quirk in some Compaq silicon:  URBs
+ * with TDs that appear to be orphaned are directly reclaimed.
  */
 static void
 dl_done_list (struct ohci_hcd *ohci)
@@ -1074,44 +1132,7 @@ dl_done_list (struct ohci_hcd *ohci)
 
 	while (td) {
 		struct td	*td_next = td->next_dl_td;
-		struct urb	*urb = td->urb;
-		urb_priv_t	*urb_priv = urb->hcpriv;
-		struct ed	*ed = td->ed;
-
-		/* update URB's length and status from TD */
-		td_done (ohci, urb, td);
-		urb_priv->td_cnt++;
-
-		/* If all this urb's TDs are done, call complete() */
-		if (urb_priv->td_cnt == urb_priv->length)
-			finish_urb (ohci, urb);
-
-		/* clean schedule:  unlink EDs that are no longer busy */
-		if (list_empty (&ed->td_list)) {
-			if (ed->state == ED_OPER)
-				start_ed_unlink (ohci, ed);
-
-		/* ... reenabling halted EDs only after fault cleanup */
-		} else if ((ed->hwINFO & cpu_to_hc32 (ohci,
-						ED_SKIP | ED_DEQUEUE))
-					== cpu_to_hc32 (ohci, ED_SKIP)) {
-			td = list_entry (ed->td_list.next, struct td, td_list);
-			if (!(td->hwINFO & cpu_to_hc32 (ohci, TD_DONE))) {
-				ed->hwINFO &= ~cpu_to_hc32 (ohci, ED_SKIP);
-				/* ... hc may need waking-up */
-				switch (ed->type) {
-				case PIPE_CONTROL:
-					ohci_writel (ohci, OHCI_CLF,
-						&ohci->regs->cmdstatus);
-					break;
-				case PIPE_BULK:
-					ohci_writel (ohci, OHCI_BLF,
-						&ohci->regs->cmdstatus);
-					break;
-				}
-			}
-		}
-
+		takeback_td(ohci, td);
 		td = td_next;
 	}
 }