From fda5b6124b45eb8d87137f8c195cbb36bebeac10 Mon Sep 17 00:00:00 2001
From: Warner Losh <imp@FreeBSD.org>
Date: Sat, 9 Aug 2003 21:05:54 +0000
Subject: [PATCH] Add code to cope more with strange conditions after careful
 study of the standard.

1) When the bridge tells us that we have a card that isn't recognized, we
   use the force register to force the CV_TEST to run.  This test causes the
   bridge to re-evaluate the card.  Once this re-evaluation process happens,
   we get a new interrupt that may say it is ready to process.  We try this up
   to 20 times.  Tests have shown that this appears to correctly reset the
   'Unknown card type' problem that I saw on my Sony PCG-505TS.
2) Take a page from OLDCARD and always read the CSC register in the ISR.
   Some TI (and it seems maybe Ricoh) chipsets require this to behave
   properly.  This work around appears to work due to some power management
   protocols that were improperly implemented.  Maybe it can be removed when
   this driver supports the full PME# protocol described in the standards.
3) Minor additional debug printf when debugging is enabled.
4) Minor additional commentary for things that are obvious only after study.

# I'm committing this from my Sony PCG-505TS using shared PCI interrupts
# and NEWCARD, but there are some issues with the Ricoh bridge still, but
# at least now I can boot with the card inserted and have it work.
---
 sys/dev/pccbb/pccbb.c | 56 ++++++++++++++++++++++++++++++++-----------
 1 file changed, 42 insertions(+), 14 deletions(-)

diff --git a/sys/dev/pccbb/pccbb.c b/sys/dev/pccbb/pccbb.c
index 357835c74986..f0178e7852f1 100644
--- a/sys/dev/pccbb/pccbb.c
+++ b/sys/dev/pccbb/pccbb.c
@@ -938,6 +938,7 @@ cbb_event_thread(void *arg)
 	struct cbb_softc *sc = arg;
 	uint32_t status;
 	int err;
+	int not_a_card = 0;
 
 	sc->flags |= CBB_KTHREAD_RUNNING;
 	while ((sc->flags & CBB_KTHREAD_DONE) == 0) {
@@ -950,10 +951,27 @@ cbb_event_thread(void *arg)
 		 */
 		mtx_lock(&Giant);
 		status = cbb_get(sc, CBB_SOCKET_STATE);
-		if ((status & CBB_STATE_CD) == 0)
-			cbb_insert(sc);
-		else
-			cbb_removal(sc);
+		DPRINTF(("Status is 0x%x\n", status));
+		if (status & CBB_STATE_NOT_A_CARD) {
+			/*
+			 * Up to 20 times, try to rescan the card when we
+			 * see NOT_A_CARD.
+			 */
+			if (not_a_card++ < 20) {
+				DEVPRINTF((sc->dev,
+				    "Not a card bit set, rescanning\n"));
+				cbb_setb(sc, CBB_SOCKET_FORCE, CBB_FORCE_CV_TEST);
+			} else {
+				device_printf(sc->dev,
+				    "Can't determine card type\n");
+			}
+		} else {
+			not_a_card = 0;		/* We know card type */
+			if ((status & CBB_STATE_CD) == 0)
+				cbb_insert(sc);
+			else
+				cbb_removal(sc);
+		}
 		mtx_unlock(&Giant);
 
 		/*
@@ -1052,7 +1070,8 @@ cbb_intr(void *arg)
 	 * This ISR needs work XXX
 	 */
 	sockevent = cbb_get(sc, CBB_SOCKET_EVENT);
-	if (sockevent) {
+	if (sockevent != 0) {
+		DPRINTF(("CBB EVENT 0x%x\n", sockevent));
 		/* ack the interrupt */
 		cbb_setb(sc, CBB_SOCKET_EVENT, sockevent);
 
@@ -1073,19 +1092,28 @@ cbb_intr(void *arg)
 			cbb_clrb(sc, CBB_SOCKET_MASK, CBB_SOCKET_MASK_CD);
 			mtx_lock(&sc->mtx);
 			sc->flags &= ~CBB_CARD_OK;
+			DPRINTF(("Waking up thread\n"));
 			cv_signal(&sc->cv);
 			mtx_unlock(&sc->mtx);
 		}
-		if (sockevent & CBB_SOCKET_EVENT_CSTS) {
-			DPRINTF((" cstsevent occured: 0x%08x\n",
-			    cbb_get(sc, CBB_SOCKET_STATE)));
-		}
-		if (sockevent & CBB_SOCKET_EVENT_POWER) {
-			DPRINTF((" pwrevent occured: 0x%08x\n",
-			    cbb_get(sc, CBB_SOCKET_STATE)));
-		}
-		/* Other bits? */
 	}
+	/*
+	 * Some chips also require us to read the old ExCA registe for
+	 * card status change when we route CSC vis PCI.  This isn't supposed
+	 * to be required, but it clears the interrupt state on some chipsets.
+	 * Maybe there's a setting that would obviate its need.  Maybe we
+	 * should test the status bits and deal with them, but so far we've
+	 * not found any machines that don't also give us the socket status
+	 * indication above.
+	 *
+	 * We have to call this unconditionally because some bridges deliver
+	 * the even independent of the CBB_SOCKET_EVENT_CD above.
+	 */
+	exca_getb(&sc->exca, EXCA_CSC);
+
+	/*
+	 * If the card is OK, call all the interrupt handlers.
+ 	 */
 	if (sc->flags & CBB_CARD_OK) {
 		STAILQ_FOREACH(ih, &sc->intr_handlers, entries) {
 			if ((ih->flags & INTR_MPSAFE) != 0)