From 0014abfcc412e5ed4440bb2577345b8c5a67e9dd Mon Sep 17 00:00:00 2001
From: Gleb Smirnoff <glebius@FreeBSD.org>
Date: Thu, 22 Dec 2005 09:09:39 +0000
Subject: [PATCH] Add a quirk to fix resume on some laptops.

Reported by:	joe
Reported by:	Huang wen hui <huang gddsn.org.cn>
Reported by:	Jacques Garrigue <garrigue math.nagoya-u.ac.jp>
PR:		kern/89825
---
 sys/dev/em/if_em.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/sys/dev/em/if_em.c b/sys/dev/em/if_em.c
index 8f8f465571e..081a24332f6 100644
--- a/sys/dev/em/if_em.c
+++ b/sys/dev/em/if_em.c
@@ -1048,6 +1048,15 @@ em_intr(void *arg)
 		else if (reg_icr == 0)
 			break;
 
+		/*
+		 * XXX: some laptops trigger several spurious interrupts
+		 * on em(4) when in the resume cycle. The ICR register
+		 * reports all-ones value in this case. Processing such
+		 * interrupts would lead to a freeze. I don't know why.
+		 */
+		if (reg_icr == 0xffffffff)
+			break;
+
 		if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
 			em_process_receive_interrupts(adapter, -1);
 			em_clean_transmit_interrupts(adapter);