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>

1 files changed, 22 insertions, 2 deletions

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 40002ae7db2b..14d0c89ada2a 100644
--- 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");