Restore udelay in poll mode

index 7222a18..828c752 100644
@@ -73,6 +73,7 @@ enum ec_event {
 
 #define ACPI_EC_DELAY		500	/* Wait 500ms max. during EC ops */
 #define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */
+#define ACPI_EC_UDELAY		100	/* Wait 100us before polling EC again */
 
 enum {
 	EC_FLAGS_WAIT_GPE = 0,		/* Don't check status until GPE arrives */

@@ -227,6 +228,7 @@ static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 		while (time_before(jiffies, delay)) {
 			if (acpi_ec_check_status(ec, event))
 				goto end;
+			udelay(ACPI_EC_UDELAY);
 		}
 	}
 	pr_err(PREFIX "acpi_ec_wait timeout,"

index 828c752..63e0ac2 100644
@@ -84,6 +84,7 @@ enum {
 	EC_FLAGS_NO_WDATA_GPE,		/* Don't expect WDATA GPE event */
 	EC_FLAGS_WDATA,			/* Data is being written */
 	EC_FLAGS_NO_OBF1_GPE,		/* Don't expect GPE before read */
+	EC_FLAGS_RESCHEDULE_POLL	/* Re-schedule poll */
 };
 
 static int acpi_ec_remove(struct acpi_device *device, int type);

@@ -130,6 +131,7 @@ static struct acpi_ec {
 	struct mutex lock;
 	wait_queue_head_t wait;
 	struct list_head list;
+	struct delayed_work work;
 	u8 handlers_installed;
 } *boot_ec, *first_ec;
 

@@ -178,6 +180,20 @@ static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
 	return 0;
 }
 
+static void ec_schedule_ec_poll(struct acpi_ec *ec)
+{
+	if (test_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags))
+		schedule_delayed_work(&ec->work,
+				      msecs_to_jiffies(ACPI_EC_DELAY));
+}
+
+static void ec_switch_to_poll_mode(struct acpi_ec *ec)
+{
+	clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
+	acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
+	set_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
+}
+
 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 {
 	int ret = 0;

@@ -218,7 +234,8 @@ static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 				if (printk_ratelimit())
 					pr_info(PREFIX "missing confirmations, "
 						"switch off interrupt mode.\n");
-				clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
+				ec_switch_to_poll_mode(ec);
+				ec_schedule_ec_poll(ec);
 			}
 			goto end;
 		}

@@ -529,28 +546,37 @@ static u32 acpi_ec_gpe_handler(void *data)
 {
 	acpi_status status = AE_OK;
 	struct acpi_ec *ec = data;
+	u8 state = acpi_ec_read_status(ec);
 
 	pr_debug(PREFIX "~~~> interrupt\n");
 	clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 	if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
 		wake_up(&ec->wait);
 
-	if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_SCI) {
+	if (state & ACPI_EC_FLAG_SCI) {
 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 			status = acpi_os_execute(OSL_EC_BURST_HANDLER,
 				acpi_ec_gpe_query, ec);
-	} else if (unlikely(!test_bit(EC_FLAGS_GPE_MODE, &ec->flags))) {
+	} else if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
+		   in_interrupt()) {
 		/* this is non-query, must be confirmation */
 		if (printk_ratelimit())
 			pr_info(PREFIX "non-query interrupt received,"
 				" switching to interrupt mode\n");
 		set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
+		clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
 	}
-
+	ec_schedule_ec_poll(ec);
 	return ACPI_SUCCESS(status) ?
 	    ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 }
 
+static void do_ec_poll(struct work_struct *work)
+{
+	struct acpi_ec *ec = container_of(work, struct acpi_ec, work.work);
+	(void)acpi_ec_gpe_handler(ec);
+}
+
 /* --------------------------------------------------------------------------
                              Address Space Management
    -------------------------------------------------------------------------- */

@@ -711,6 +737,7 @@ static struct acpi_ec *make_acpi_ec(void)
 	mutex_init(&ec->lock);
 	init_waitqueue_head(&ec->wait);
 	INIT_LIST_HEAD(&ec->list);
+	INIT_DELAYED_WORK_DEFERRABLE(&ec->work, do_ec_poll);
 	return ec;
 }
 

@@ -752,8 +779,15 @@ ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 	return AE_CTRL_TERMINATE;
 }
 
+static void ec_poll_stop(struct acpi_ec *ec)
+{
+	clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
+	cancel_delayed_work(&ec->work);
+}
+
 static void ec_remove_handlers(struct acpi_ec *ec)
 {
+	ec_poll_stop(ec);
 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 		pr_err(PREFIX "failed to remove space handler\n");

@@ -899,6 +933,7 @@ static int acpi_ec_start(struct acpi_device *device)
 
 	/* EC is fully operational, allow queries */
 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
+	ec_schedule_ec_poll(ec);
 	return ret;
 }
 

index 63e0ac2..1a7949c 100644
@@ -248,9 +248,9 @@ static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 			udelay(ACPI_EC_UDELAY);
 		}
 	}
-	pr_err(PREFIX "acpi_ec_wait timeout,"
-			       " status = %d, expect_event = %d\n",
-			       acpi_ec_read_status(ec), event);
+	pr_err(PREFIX "acpi_ec_wait timeout, status = 0x%2.2x, event = %s\n",
+		acpi_ec_read_status(ec),
+		(event == ACPI_EC_EVENT_OBF_1) ? "\"b0=1\"" : "\"b1=0\"");
 	ret = -ETIME;
       end:
 	clear_bit(EC_FLAGS_ADDRESS, &ec->flags);

@@ -264,8 +264,8 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
 {
 	int result = 0;
 	set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
-	acpi_ec_write_cmd(ec, command);
 	pr_debug(PREFIX "transaction start\n");
+	acpi_ec_write_cmd(ec, command);
 	for (; wdata_len > 0; --wdata_len) {
 		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
 		if (result) {

index 1a7949c..7f07b68 100644
@@ -79,11 +79,7 @@ enum {
 	EC_FLAGS_WAIT_GPE = 0,		/* Don't check status until GPE arrives */
 	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
 	EC_FLAGS_GPE_MODE,		/* Expect GPE to be sent for status change */
-	EC_FLAGS_NO_ADDRESS_GPE,	/* Expect GPE only for non-address event */
-	EC_FLAGS_ADDRESS,		/* Address is being written */
-	EC_FLAGS_NO_WDATA_GPE,		/* Don't expect WDATA GPE event */
-	EC_FLAGS_WDATA,			/* Data is being written */
-	EC_FLAGS_NO_OBF1_GPE,		/* Don't expect GPE before read */
+	EC_FLAGS_NO_GPE,		/* Don't use GPE mode */
 	EC_FLAGS_RESCHEDULE_POLL	/* Re-schedule poll */
 };
 

@@ -189,6 +185,7 @@ static void ec_schedule_ec_poll(struct acpi_ec *ec)
 
 static void ec_switch_to_poll_mode(struct acpi_ec *ec)
 {
+	set_bit(EC_FLAGS_NO_GPE, &ec->flags);
 	clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 	acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 	set_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);

@@ -196,65 +193,34 @@ static void ec_switch_to_poll_mode(struct acpi_ec *ec)
 
 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 {
-	int ret = 0;
-
-	if (unlikely(event == ACPI_EC_EVENT_OBF_1 &&
-		     test_bit(EC_FLAGS_NO_OBF1_GPE, &ec->flags)))
-		force_poll = 1;
-	if (unlikely(test_bit(EC_FLAGS_ADDRESS, &ec->flags) &&
-		     test_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags)))
-		force_poll = 1;
-	if (unlikely(test_bit(EC_FLAGS_WDATA, &ec->flags) &&
-		     test_bit(EC_FLAGS_NO_WDATA_GPE, &ec->flags)))
-		force_poll = 1;
 	if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&
 	    likely(!force_poll)) {
 		if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),
 				       msecs_to_jiffies(ACPI_EC_DELAY)))
-			goto end;
+			return 0;
 		clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 		if (acpi_ec_check_status(ec, event)) {
-			if (event == ACPI_EC_EVENT_OBF_1) {
-				/* miss OBF_1 GPE, don't expect it */
-				pr_info(PREFIX "missing OBF confirmation, "
-					"don't expect it any longer.\n");
-				set_bit(EC_FLAGS_NO_OBF1_GPE, &ec->flags);
-			} else if (test_bit(EC_FLAGS_ADDRESS, &ec->flags)) {
-				/* miss address GPE, don't expect it anymore */
-				pr_info(PREFIX "missing address confirmation, "
-					"don't expect it any longer.\n");
-				set_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags);
-			} else if (test_bit(EC_FLAGS_WDATA, &ec->flags)) {
-				/* miss write data GPE, don't expect it */
-				pr_info(PREFIX "missing write data confirmation, "
-					"don't expect it any longer.\n");
-				set_bit(EC_FLAGS_NO_WDATA_GPE, &ec->flags);
-			} else {
-				/* missing GPEs, switch back to poll mode */
-				if (printk_ratelimit())
-					pr_info(PREFIX "missing confirmations, "
+			/* missing GPEs, switch back to poll mode */
+			if (printk_ratelimit())
+				pr_info(PREFIX "missing confirmations, "
 						"switch off interrupt mode.\n");
-				ec_switch_to_poll_mode(ec);
-				ec_schedule_ec_poll(ec);
-			}
-			goto end;
+			ec_switch_to_poll_mode(ec);
+			ec_schedule_ec_poll(ec);
+			return 0;
 		}
 	} else {
 		unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 		clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 		while (time_before(jiffies, delay)) {
 			if (acpi_ec_check_status(ec, event))
-				goto end;
+				return 0;
 			udelay(ACPI_EC_UDELAY);
 		}
 	}
 	pr_err(PREFIX "acpi_ec_wait timeout, status = 0x%2.2x, event = %s\n",
 		acpi_ec_read_status(ec),
 		(event == ACPI_EC_EVENT_OBF_1) ? "\"b0=1\"" : "\"b1=0\"");
-	ret = -ETIME;
-      end:
-	clear_bit(EC_FLAGS_ADDRESS, &ec->flags);
-	return ret;
+	return -ETIME;
 }
 
 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,

@@ -273,15 +239,11 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
 			       "write_cmd timeout, command = %d\n", command);
 			goto end;
 		}
-		/* mark the address byte written to EC */
-		if (rdata_len + wdata_len > 1)
-			set_bit(EC_FLAGS_ADDRESS, &ec->flags);
 		set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 		acpi_ec_write_data(ec, *(wdata++));
 	}
 
 	if (!rdata_len) {
-		set_bit(EC_FLAGS_WDATA, &ec->flags);
 		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
 		if (result) {
 			pr_err(PREFIX

@@ -558,6 +520,7 @@ static u32 acpi_ec_gpe_handler(void *data)
 			status = acpi_os_execute(OSL_EC_BURST_HANDLER,
 				acpi_ec_gpe_query, ec);
 	} else if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
+		   !test_bit(EC_FLAGS_NO_GPE, &ec->flags) &&
 		   in_interrupt()) {
 		/* this is non-query, must be confirmation */
 		if (printk_ratelimit())

index 7f07b68..da67d22 100644
@@ -83,28 +83,6 @@ enum {
 	EC_FLAGS_RESCHEDULE_POLL	/* Re-schedule poll */
 };
 
-static int acpi_ec_remove(struct acpi_device *device, int type);
-static int acpi_ec_start(struct acpi_device *device);
-static int acpi_ec_stop(struct acpi_device *device, int type);
-static int acpi_ec_add(struct acpi_device *device);
-
-static const struct acpi_device_id ec_device_ids[] = {
-	{"PNP0C09", 0},
-	{"", 0},
-};
-
-static struct acpi_driver acpi_ec_driver = {
-	.name = "ec",
-	.class = ACPI_EC_CLASS,
-	.ids = ec_device_ids,
-	.ops = {
-		.add = acpi_ec_add,
-		.remove = acpi_ec_remove,
-		.start = acpi_ec_start,
-		.stop = acpi_ec_stop,
-		},
-};
-
 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
 /* External interfaces use first EC only, so remember */
 typedef int (*acpi_ec_query_func) (void *data);

@@ -924,6 +902,11 @@ int __init acpi_boot_ec_enable(void)
 	return -EFAULT;
 }
 
+static const struct acpi_device_id ec_device_ids[] = {
+	{"PNP0C09", 0},
+	{"", 0},
+};
+
 int __init acpi_ec_ecdt_probe(void)
 {
 	int ret;

@@ -973,6 +956,39 @@ int __init acpi_ec_ecdt_probe(void)
 	return -ENODEV;
 }
 
+static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
+{
+	struct acpi_ec *ec = acpi_driver_data(device);
+	/* Stop using GPE */
+	set_bit(EC_FLAGS_NO_GPE, &ec->flags);
+	clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
+	acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
+	return 0;
+}
+
+static int acpi_ec_resume(struct acpi_device *device)
+{
+	struct acpi_ec *ec = acpi_driver_data(device);
+	/* Enable use of GPE back */
+	clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
+	acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
+	return 0;
+}
+
+static struct acpi_driver acpi_ec_driver = {
+	.name = "ec",
+	.class = ACPI_EC_CLASS,
+	.ids = ec_device_ids,
+	.ops = {
+		.add = acpi_ec_add,
+		.remove = acpi_ec_remove,
+		.start = acpi_ec_start,
+		.stop = acpi_ec_stop,
+		.suspend = acpi_ec_suspend,
+		.resume = acpi_ec_resume,
+		},
+};
+
 static int __init acpi_ec_init(void)
 {
 	int result = 0;

index da67d22..284d421 100644
@@ -106,6 +106,7 @@ static struct acpi_ec {
 	wait_queue_head_t wait;
 	struct list_head list;
 	struct delayed_work work;
+	atomic_t irq_count;
 	u8 handlers_installed;
 } *boot_ec, *first_ec;
 

@@ -171,6 +172,7 @@ static void ec_switch_to_poll_mode(struct acpi_ec *ec)
 
 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 {
+	atomic_set(&ec->irq_count, 0);
 	if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&
 	    likely(!force_poll)) {
 		if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),

@@ -489,6 +491,12 @@ static u32 acpi_ec_gpe_handler(void *data)
 	u8 state = acpi_ec_read_status(ec);
 
 	pr_debug(PREFIX "~~~> interrupt\n");
+	atomic_inc(&ec->irq_count);
+	if (atomic_read(&ec->irq_count) > 5) {
+		pr_err(PREFIX "GPE storm detected, disabling EC GPE\n");
+		ec_switch_to_poll_mode(ec);
+		goto end;
+	}
 	clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 	if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
 		wake_up(&ec->wait);

@@ -507,6 +515,7 @@ static u32 acpi_ec_gpe_handler(void *data)
 		set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 		clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
 	}
+end:
 	ec_schedule_ec_poll(ec);
 	return ACPI_SUCCESS(status) ?
 	    ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;

@@ -679,6 +688,7 @@ static struct acpi_ec *make_acpi_ec(void)
 	init_waitqueue_head(&ec->wait);
 	INIT_LIST_HEAD(&ec->list);
 	INIT_DELAYED_WORK_DEFERRABLE(&ec->work, do_ec_poll);
+	atomic_set(&ec->irq_count, 0);
 	return ec;
 }
 

index da67d22..f0e8216 100644
@@ -106,6 +106,7 @@ static struct acpi_ec {
 	wait_queue_head_t wait;
 	struct list_head list;
 	struct delayed_work work;
+	atomic_t irq_count;
 	u8 handlers_installed;
 } *boot_ec, *first_ec;
 

@@ -171,6 +172,7 @@ static void ec_switch_to_poll_mode(struct acpi_ec *ec)
 
 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 {
+	atomic_set(&ec->irq_count, 0);
 	if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&
 	    likely(!force_poll)) {
 		if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),

@@ -489,6 +491,12 @@ static u32 acpi_ec_gpe_handler(void *data)
 	u8 state = acpi_ec_read_status(ec);
 
 	pr_debug(PREFIX "~~~> interrupt\n");
+	atomic_inc(&ec->irq_count);
+	if (atomic_read(&ec->irq_count) > 5) {
+		pr_err(PREFIX "GPE storm detected, disabling EC GPE\n");
+		ec_switch_to_poll_mode(ec);
+		goto end;
+	}
 	clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 	if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
 		wake_up(&ec->wait);

@@ -507,6 +515,7 @@ static u32 acpi_ec_gpe_handler(void *data)
 		set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 		clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
 	}
+end:
 	ec_schedule_ec_poll(ec);
 	return ACPI_SUCCESS(status) ?
 	    ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;

@@ -515,6 +524,7 @@ static u32 acpi_ec_gpe_handler(void *data)
 static void do_ec_poll(struct work_struct *work)
 {
 	struct acpi_ec *ec = container_of(work, struct acpi_ec, work.work);
+	atomic_set(&ec->irq_count, 0);
 	(void)acpi_ec_gpe_handler(ec);
 }
 

@@ -679,6 +689,7 @@ static struct acpi_ec *make_acpi_ec(void)
 	init_waitqueue_head(&ec->wait);
 	INIT_LIST_HEAD(&ec->list);
 	INIT_DELAYED_WORK_DEFERRABLE(&ec->work, do_ec_poll);
+	atomic_set(&ec->irq_count, 0);
 	return ec;
 }