ACPI: ec: Remove expect_event and all races around it.

Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 38 insertions, 46 deletions

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 94b983b9cfba..1514e71b723d 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -46,6 +46,9 @@ ACPI_MODULE_NAME("acpi_ec")
 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
 #define ACPI_EC_FILE_INFO               "info"
 
+#undef PREFIX
+#define PREFIX                          "ACPI: EC: "
+
 /* EC status register */
 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
@@ -101,7 +104,6 @@ struct acpi_ec {
         unsigned long data_addr;
         unsigned long global_lock;
         struct semaphore sem;
-        unsigned int expect_event;
         atomic_t leaving_burst; /* 0 : No, 1 : Yes, 2: abort */
         wait_queue_head_t wait;
 } *ec_ecdt;
@@ -155,34 +157,25 @@ static int acpi_ec_check_status(struct acpi_ec *ec, u8 event)
 
 static int acpi_ec_wait(struct acpi_ec *ec, u8 event)
 {
-        int i = (acpi_ec_mode == EC_POLL) ? ACPI_EC_UDELAY_COUNT : 0;
-        long time_left;
-
-        ec->expect_event = event;
-        if (acpi_ec_check_status(ec, event)) {
-                ec->expect_event = 0;
-                return 0;
-        }
-
-        do {
-                if (acpi_ec_mode == EC_POLL) {
-                        udelay(ACPI_EC_UDELAY);
-                } else {
-                        time_left = wait_event_timeout(ec->wait,
-                                    !ec->expect_event,
-                                    msecs_to_jiffies(ACPI_EC_DELAY));
-                        if (time_left > 0) {
-                                ec->expect_event = 0;
+        if (acpi_ec_mode == EC_POLL) {
+                int i;
+                for (i = 0; i < ACPI_EC_UDELAY_COUNT; ++i) {
+                        if (acpi_ec_check_status(ec, event))
                                 return 0;
-                        }
+                        udelay(ACPI_EC_UDELAY);
                 }
-                if (acpi_ec_check_status(ec, event)) {
-                        ec->expect_event = 0;
+        } else {
+                if (wait_event_timeout(ec->wait,
+                                       acpi_ec_check_status(ec, event),
+                                       msecs_to_jiffies(ACPI_EC_DELAY)) ||
+                    acpi_ec_check_status(ec, event)) {
                         return 0;
+                } else {
+                        printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
+                               " status = %d, expect_event = %d\n",
+                             acpi_ec_read_status(ec), event);
                 }
-        } while (--i > 0);
-
-        ec->expect_event = 0;
+        }
 
         return -ETIME;
 }
@@ -243,32 +236,41 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
                                         const u8 *wdata, unsigned wdata_len,
                                         u8 *rdata, unsigned rdata_len)
 {
-        int result;
+        int result = 0;
 
         acpi_ec_write_cmd(ec, command);
 
         for (; wdata_len > 0; wdata_len --) {
                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
-                if (result)
-                        return result;
+                if (result) {
+                        printk(KERN_ERR PREFIX "write_cmd timeout, command = %d\n",
+                             command);
+                        goto end;
+                }
                 acpi_ec_write_data(ec, *(wdata++));
         }
 
         if (!rdata_len) {
                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
-                if (result)
-                        return result;
+                if (result) {
+                        printk(KERN_ERR PREFIX "finish-write timeout, command = %d\n",
+                             command);
+                        goto end;
+                }
         }
 
         for (; rdata_len > 0; rdata_len --) {
                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1);
-                if (result)
-                        return result;
+                if (result) {
+                        printk(KERN_ERR PREFIX "read timeout, command = %d\n",
+                             command);
+                        goto end;
+                }
 
                 *(rdata++) = acpi_ec_read_data(ec);
         }
-
-        return 0;
+      end:
+        return result;
 }
 
 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
@@ -419,11 +421,6 @@ static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
                                 Event Management
    -------------------------------------------------------------------------- */
 
-struct acpi_ec_query_data {
-        acpi_handle handle;
-        u8 data;
-};
-
 static void acpi_ec_gpe_query(void *ec_cxt)
 {
         struct acpi_ec *ec = (struct acpi_ec *)ec_cxt;
@@ -443,7 +440,7 @@ static void acpi_ec_gpe_query(void *ec_cxt)
 
         snprintf(object_name, 8, "_Q%2.2X", value);
 
-        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluating %s", object_name));
+        printk(KERN_INFO PREFIX "evaluating %s\n", object_name);
 
         acpi_evaluate_object(ec->handle, object_name, NULL, NULL);
 
@@ -460,17 +457,12 @@ static u32 acpi_ec_gpe_handler(void *data)
         acpi_clear_gpe(NULL, ec->gpe_bit, ACPI_ISR);
 
         if (acpi_ec_mode == EC_INTR) {
-                if (acpi_ec_check_status(ec, ec->expect_event)) {
-                        ec->expect_event = 0;
-                        wake_up(&ec->wait);
-                }
+                wake_up(&ec->wait);
         }
 
         value = acpi_ec_read_status(ec);
         if (value & ACPI_EC_FLAG_SCI) {
                 status = acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query, ec);
-                return status == AE_OK ?
-                    ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
         }
         acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_ISR);
         return status == AE_OK ?