From 414f7ec8bd7c55f3193d7cbebb7d8bdbfc52bdd2 Mon Sep 17 00:00:00 2001
From: Warner Losh <imp@FreeBSD.org>
Date: Fri, 5 Dec 2008 04:43:25 +0000
Subject: [PATCH] Implement a method described in NetBSD PR 36652 for coping
 with the BAD VCC bit.

---
 sys/dev/pccbb/pccbb.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/sys/dev/pccbb/pccbb.c b/sys/dev/pccbb/pccbb.c
index 8703ab8b655..5cec8f4de2e 100644
--- a/sys/dev/pccbb/pccbb.c
+++ b/sys/dev/pccbb/pccbb.c
@@ -837,7 +837,18 @@ cbb_power(device_t brdev, int volts)
 	}
 	if (status & CBB_STATE_BAD_VCC_REQ) {
 		device_printf(sc->dev, "Bad Vcc requested\n");	
-		/* XXX Do we want to do something to mitigate things here? */
+		/*
+		 * Turn off the power, and try again.  Retrigger other
+		 * active interrupts via force register.  From NetBSD
+		 * PR 36652, coded by me to description there.
+		 */
+		sock_ctrl &= ~CBB_SOCKET_CTRL_VCCMASK;
+		sock_ctrl &= ~CBB_SOCKET_CTRL_VPPMASK;
+		cbb_set(sc, CBB_SOCKET_CONTROL, sock_ctrl);
+		status &= ~CBB_STATE_BAD_VCC_REQ;
+		status &= ~CBB_STATE_DATA_LOST;
+		status |= CBB_FORCE_CV_TEST;
+		cbb_set(sc, CBB_SOCKET_FORCE, status);
 		goto done;
 	}
 	if (sc->chipset == CB_TOPIC97) {