ACPI: EC: make kernel messages more useful when GPE storm is detected

Make sure we can tell if the GPE storm workaround gets activated,
and avoid flooding the logs afterwards.

http://bugzilla.kernel.org/show_bug.cgi?id=11841
"plenty of line "ACPI: EC: non-query interrupt received,
 switching to interrupt mode" in dmesg"
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Acked-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/ec.c

@@ -286,7 +286,8 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 		acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 	} else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 		   t->irq_count > ACPI_EC_STORM_THRESHOLD) {
-		pr_debug(PREFIX "GPE storm detected\n");
+		pr_info(PREFIX "GPE storm detected, "
+			"transactions will use polling mode\n");
 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 	}
 	return ret;
@@ -566,9 +567,15 @@ static u32 acpi_ec_gpe_handler(void *data)
 	if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 	    !test_bit(EC_FLAGS_NO_GPE, &ec->flags)) {
 		/* this is non-query, must be confirmation */
+		if (!test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 			if (printk_ratelimit())
 				pr_info(PREFIX "non-query interrupt received,"
 					" switching to interrupt mode\n");
+		} else {
+			/* hush, STORM switches the mode every transaction */
+			pr_debug(PREFIX "non-query interrupt received,"
+				" switching to interrupt mode\n");
+		}
 		set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 	}
 	return ACPI_INTERRUPT_HANDLED;