From: Andi Kleen <ak@suse.de>

I have a weird KVM that refuses to switch consoles when the keyboard
controller doesn't process key presses.  Actually it switches, but only
after a long delay which usually drives me crazy.

This patch changes the panic loop to eat keys from the keyboard controller
on i386 boxes.  With that I can switch consoles after a panic.

The ioport should be available on all PC like boxes, the reset code also
depends on it being at a fixed place.

ioport.c is not the best place in the world to place the function, but I
didn't find a better one.  It cannot be inlined to avoid include hell.



 arch/i386/kernel/ioport.c |   13 +++++++++++++
 include/asm-i386/system.h |    3 +++
 kernel/panic.c            |    7 +++++--
 3 files changed, 21 insertions(+), 2 deletions(-)

diff -puN arch/i386/kernel/ioport.c~eat-keys-on-panic arch/i386/kernel/ioport.c
--- 25/arch/i386/kernel/ioport.c~eat-keys-on-panic	2003-05-31 10:29:44.000000000 -0700
+++ 25-akpm/arch/i386/kernel/ioport.c	2003-05-31 10:30:03.000000000 -0700
@@ -15,6 +15,9 @@
 #include <linux/stddef.h>
 #include <linux/slab.h>
 #include <linux/thread_info.h>
+#include <linux/delay.h>
+
+#include <asm/io.h>
 
 /* Set EXTENT bits starting at BASE in BITMAP to value TURN_ON. */
 static void set_bitmap(unsigned long *bitmap, short base, short extent, int new_value)
@@ -129,3 +132,13 @@ asmlinkage int sys_iopl(unsigned long un
 	set_thread_flag(TIF_IRET);
 	return 0;
 }
+
+/* Some KVMs don't switch consoles unless the keyboard is served. */
+void eat_key(void)
+{
+	if (inb(0x60) & 1) {
+		mdelay(1);
+		inb(0x64);
+	}
+	mdelay(1);
+}
diff -puN include/asm-i386/system.h~eat-keys-on-panic include/asm-i386/system.h
--- 25/include/asm-i386/system.h~eat-keys-on-panic	2003-05-31 10:29:44.000000000 -0700
+++ 25-akpm/include/asm-i386/system.h	2003-05-31 10:29:44.000000000 -0700
@@ -476,4 +476,7 @@ extern int is_sony_vaio_laptop;
 #define BROKEN_PNP_BIOS		0x0004
 #define BROKEN_CPUFREQ		0x0008
 
+#define HAVE_EAT_KEY
+void eat_key(void);
+
 #endif
diff -puN kernel/panic.c~eat-keys-on-panic kernel/panic.c
--- 25/kernel/panic.c~eat-keys-on-panic	2003-05-31 10:29:44.000000000 -0700
+++ 25-akpm/kernel/panic.c	2003-05-31 10:29:44.000000000 -0700
@@ -96,8 +96,11 @@ NORET_TYPE void panic(const char * fmt, 
         disabled_wait(caller);
 #endif
 	local_irq_enable();
-	for (;;)
-		;
+	for (;;) { 
+#ifdef HAVE_EAT_KEY
+		eat_key();
+#endif
+	} 
 }
 
 /**

_