Ed Tomlinson has a machine on which some other device grabs IRQ12 first, and
the 8042 doesn't work.  Enabling shared iRQs in the 8042 driver fixes it up. 
Alan has confirmed that this is OK.



 drivers/input/serio/i8042.c |   15 ++++++++++++---
 1 files changed, 12 insertions(+), 3 deletions(-)

diff -puN drivers/input/serio/i8042.c~i8042-share-irqs drivers/input/serio/i8042.c
--- 25/drivers/input/serio/i8042.c~i8042-share-irqs	2003-04-08 14:44:19.000000000 -0700
+++ 25-akpm/drivers/input/serio/i8042.c	2003-04-08 14:47:28.000000000 -0700
@@ -62,6 +62,12 @@ static unsigned char i8042_last_e0;
 static unsigned char i8042_mux_open;
 struct timer_list i8042_timer;
 
+/*
+ * Shared IRQ's require a device pointer, but this driver doesn't support
+ * multiple devices
+ */
+#define i8042_request_irq_cookie (&i8042_timer)
+
 static unsigned long i8042_unxlate_seen[256 / BITS_PER_LONG];
 static unsigned char i8042_unxlate_table[128] = {
 	  0,118, 22, 30, 38, 37, 46, 54, 61, 62, 70, 69, 78, 85,102, 13,
@@ -235,7 +241,8 @@ static int i8042_open(struct serio *port
 		if (i8042_mux_open++)
 			return 0;
 
-	if (request_irq(values->irq, i8042_interrupt, 0, "i8042", NULL)) {
+	if (request_irq(values->irq, i8042_interrupt,
+			SA_SHIRQ, "i8042", i8042_request_irq_cookie)) {
 		printk(KERN_ERR "i8042.c: Can't get irq %d for %s, unregistering the port.\n", values->irq, values->name);
 		values->exists = 0;
 		serio_unregister_port(port);
@@ -570,7 +577,8 @@ static int __init i8042_check_mux(struct
  * Check if AUX irq is available.
  */
 
-	if (request_irq(values->irq, i8042_interrupt, 0, "i8042", NULL))
+	if (request_irq(values->irq, i8042_interrupt, SA_SHIRQ,
+				"i8042", i8042_request_irq_cookie))
                 return -1;
 	free_irq(values->irq, NULL);
 
@@ -641,7 +649,8 @@ static int __init i8042_check_aux(struct
  * in trying to detect AUX presence.
  */
 
-	if (request_irq(values->irq, i8042_interrupt, 0, "i8042", NULL))
+	if (request_irq(values->irq, i8042_interrupt, SA_SHIRQ,
+				"i8042", i8042_request_irq_cookie))
                 return -1;
 	free_irq(values->irq, NULL);
 

_