ACPI / EC: Add GPE reference counting debugging messages

This patch enhances debugging with the GPE reference count messages added.
No functional changes.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 40002ae..14d0c89 100644 (file)
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -31,6 +31,7 @@
 
 /* Uncomment next line to get verbose printout */
 /* #define DEBUG */
+#define DEBUG_REF 0
 #define pr_fmt(fmt) "ACPI : EC: " fmt
 
 #include <linux/kernel.h>
@@ -90,6 +91,13 @@ enum {
 #define ACPI_EC_COMMAND_POLL           0x01 /* Available for command byte */
 #define ACPI_EC_COMMAND_COMPLETE       0x02 /* Completed last byte */
 
+#define ec_debug_ref(ec, fmt, ...)                                     \
+       do {                                                            \
+               if (DEBUG_REF)                                          \
+                       pr_debug("%lu: " fmt, ec->reference_count,      \
+                                ## __VA_ARGS__);                       \
+       } while (0)
+
 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 module_param(ec_delay, uint, 0644);
@@ -356,12 +364,14 @@ static void acpi_ec_submit_event(struct acpi_ec *ec)
        /* Hold reference for pending event */
        if (!acpi_ec_submit_flushable_request(ec, true))
                return;
+       ec_debug_ref(ec, "Increase event\n");
        if (!test_and_set_bit(EC_FLAGS_EVENT_PENDING, &ec->flags)) {
                pr_debug("***** Event query started *****\n");
                schedule_work(&ec->work);
                return;
        }
        acpi_ec_complete_request(ec);
+       ec_debug_ref(ec, "Decrease event\n");
 }
 
 static void acpi_ec_complete_event(struct acpi_ec *ec)
@@ -371,6 +381,7 @@ static void acpi_ec_complete_event(struct acpi_ec *ec)
                pr_debug("***** Event query stopped *****\n");
                /* Unhold reference for pending event */
                acpi_ec_complete_request(ec);
+               ec_debug_ref(ec, "Decrease event\n");
                /* Check if there is another SCI_EVT detected */
                acpi_ec_submit_event(ec);
        }
@@ -381,12 +392,14 @@ static void acpi_ec_submit_detection(struct acpi_ec *ec)
        /* Hold reference for query submission */
        if (!acpi_ec_submit_flushable_request(ec, false))
                return;
+       ec_debug_ref(ec, "Increase query\n");
        if (!test_and_set_bit(EC_FLAGS_EVENT_DETECTED, &ec->flags)) {
                pr_debug("***** Event detection blocked *****\n");
                acpi_ec_submit_event(ec);
                return;
        }
        acpi_ec_complete_request(ec);
+       ec_debug_ref(ec, "Decrease query\n");
 }
 
 static void acpi_ec_complete_detection(struct acpi_ec *ec)
@@ -396,6 +409,7 @@ static void acpi_ec_complete_detection(struct acpi_ec *ec)
                pr_debug("***** Event detetion unblocked *****\n");
                /* Unhold reference for query submission */
                acpi_ec_complete_request(ec);
+               ec_debug_ref(ec, "Decrease query\n");
        }
 }
 
@@ -570,6 +584,7 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
                ret = -EINVAL;
                goto unlock;
        }
+       ec_debug_ref(ec, "Increase command\n");
        /* following two actions should be kept atomic */
        ec->curr = t;
        pr_debug("***** Command(%s) started *****\n",
@@ -585,6 +600,7 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
        ec->curr = NULL;
        /* Disable GPE for command processing (IBF=0/OBF=1) */
        acpi_ec_complete_request(ec);
+       ec_debug_ref(ec, "Decrease command\n");
 unlock:
        spin_unlock_irqrestore(&ec->lock, tmp);
        return ret;
@@ -746,8 +762,10 @@ static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
        if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
                pr_debug("+++++ Starting EC +++++\n");
                /* Enable GPE for event processing (SCI_EVT=1) */
-               if (!resuming)
+               if (!resuming) {
                        acpi_ec_submit_request(ec);
+                       ec_debug_ref(ec, "Increase driver\n");
+               }
                pr_info("+++++ EC started +++++\n");
        }
        spin_unlock_irqrestore(&ec->lock, flags);
@@ -776,8 +794,10 @@ static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
                wait_event(ec->wait, acpi_ec_stopped(ec));
                spin_lock_irqsave(&ec->lock, flags);
                /* Disable GPE for event processing (SCI_EVT=1) */
-               if (!suspending)
+               if (!suspending) {
                        acpi_ec_complete_request(ec);
+                       ec_debug_ref(ec, "Decrease driver\n");
+               }
                clear_bit(EC_FLAGS_STARTED, &ec->flags);
                clear_bit(EC_FLAGS_STOPPED, &ec->flags);
                pr_info("+++++ EC stopped +++++\n");