Input: i8042 - give more trust to PNP data on i386

On some boxes that don't have PS/2 mice connected at startup BIOS
completely disables AUX port and attempts to access it result in
hosed keyboard. Historically we do not trust ACPI/PNP data on
i386 and try to poke AUX port even if we did not find an active
PNP node for it. However in cases when BIOS writers got KBD port
properly described we can assume that they did the right thing
for AUX port as well.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/serio/i8042-x86ia64io.h

@@ -366,6 +366,7 @@ static void i8042_pnp_exit(void)
 static int __init i8042_pnp_init(void)
 {
 	char kbd_irq_str[4] = { 0 }, aux_irq_str[4] = { 0 };
+	int pnp_data_busted = 0;
 	int err;
 
 	if (i8042_nopnp) {
@@ -413,28 +414,49 @@ static int __init i8042_pnp_init(void)
 #endif
 
 	if (((i8042_pnp_data_reg & ~0xf) == (i8042_data_reg & ~0xf) &&
-	      i8042_pnp_data_reg != i8042_data_reg) || !i8042_pnp_data_reg) {
-		printk(KERN_WARNING "PNP: PS/2 controller has invalid data port %#x; using default %#x\n",
+	      i8042_pnp_data_reg != i8042_data_reg) ||
+	    !i8042_pnp_data_reg) {
+		printk(KERN_WARNING
+			"PNP: PS/2 controller has invalid data port %#x; "
+			"using default %#x\n",
 			i8042_pnp_data_reg, i8042_data_reg);
 		i8042_pnp_data_reg = i8042_data_reg;
+		pnp_data_busted = 1;
 	}
 
 	if (((i8042_pnp_command_reg & ~0xf) == (i8042_command_reg & ~0xf) &&
-	      i8042_pnp_command_reg != i8042_command_reg) || !i8042_pnp_command_reg) {
-		printk(KERN_WARNING "PNP: PS/2 controller has invalid command port %#x; using default %#x\n",
+	      i8042_pnp_command_reg != i8042_command_reg) ||
+	    !i8042_pnp_command_reg) {
+		printk(KERN_WARNING
+			"PNP: PS/2 controller has invalid command port %#x; "
+			"using default %#x\n",
 			i8042_pnp_command_reg, i8042_command_reg);
 		i8042_pnp_command_reg = i8042_command_reg;
+		pnp_data_busted = 1;
 	}
 
 	if (!i8042_nokbd && !i8042_pnp_kbd_irq) {
-		printk(KERN_WARNING "PNP: PS/2 controller doesn't have KBD irq; using default %d\n", i8042_kbd_irq);
+		printk(KERN_WARNING
+			"PNP: PS/2 controller doesn't have KBD irq; "
+			"using default %d\n", i8042_kbd_irq);
 		i8042_pnp_kbd_irq = i8042_kbd_irq;
+		pnp_data_busted = 1;
 	}
 
 	if (!i8042_noaux && !i8042_pnp_aux_irq) {
-		printk(KERN_WARNING "PNP: PS/2 controller doesn't have AUX irq; using default %d\n", i8042_aux_irq);
+		if (!pnp_data_busted && i8042_pnp_kbd_irq) {
+			printk(KERN_WARNING
+				"PNP: PS/2 appears to have AUX port disabled, "
+				"if this is incorrect please boot with "
+				"i8042.nopnp\n");
+			i8042_noaux = 1;
+		} else {
+			printk(KERN_WARNING
+				"PNP: PS/2 controller doesn't have AUX irq; "
+				"using default %d\n", i8042_aux_irq);
 			i8042_pnp_aux_irq = i8042_aux_irq;
 		}
+	}
 
 	i8042_data_reg = i8042_pnp_data_reg;
 	i8042_command_reg = i8042_pnp_command_reg;