ACPI: ec: Remove expect_event and all races around it. (af3fd140) · Commits · e / devices / android_kernel_fairphone_FP4

drivers/acpi/ec.c

+38 −46

Original line number	Original line	Diff line number	Diff line
	@@ -46,6 +46,9 @@ ACPI_MODULE_NAME("acpi_ec")
	#define ACPI_EC_DEVICE_NAME "Embedded Controller"		#define ACPI_EC_DEVICE_NAME "Embedded Controller"
	#define ACPI_EC_FILE_INFO "info"		#define ACPI_EC_FILE_INFO "info"

			#undef PREFIX
			#define PREFIX "ACPI: EC: "

	/* EC status register */		/* EC status register */
	#define ACPI_EC_FLAG_OBF 0x01 /* Output buffer full */		#define ACPI_EC_FLAG_OBF 0x01 /* Output buffer full */
	#define ACPI_EC_FLAG_IBF 0x02 /* Input buffer full */		#define ACPI_EC_FLAG_IBF 0x02 /* Input buffer full */
	@@ -101,7 +104,6 @@ struct acpi_ec {
	unsigned long data_addr;		unsigned long data_addr;
	unsigned long global_lock;		unsigned long global_lock;
	struct semaphore sem;		struct semaphore sem;
	unsigned int expect_event;
	atomic_t leaving_burst; /* 0 : No, 1 : Yes, 2: abort */		atomic_t leaving_burst; /* 0 : No, 1 : Yes, 2: abort */
	wait_queue_head_t wait;		wait_queue_head_t wait;
	} *ec_ecdt;		} *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)		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) {		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);		udelay(ACPI_EC_UDELAY);
			}
	} else {		} else {
	time_left = wait_event_timeout(ec->wait,		if (wait_event_timeout(ec->wait,
	!ec->expect_event,		acpi_ec_check_status(ec, event),
	msecs_to_jiffies(ACPI_EC_DELAY));		msecs_to_jiffies(ACPI_EC_DELAY)) \|\|
	if (time_left > 0) {		acpi_ec_check_status(ec, event)) {
	ec->expect_event = 0;
	return 0;		return 0;
			} else {
			printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
			" status = %d, expect_event = %d\n",
			acpi_ec_read_status(ec), event);
	}		}
	}		}
	if (acpi_ec_check_status(ec, event)) {
	ec->expect_event = 0;
	return 0;
	}
	} while (--i > 0);

	ec->expect_event = 0;

	return -ETIME;		return -ETIME;
	}		}
	@@ -243,32 +236,41 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
	const u8 *wdata, unsigned wdata_len,		const u8 *wdata, unsigned wdata_len,
	u8 *rdata, unsigned rdata_len)		u8 *rdata, unsigned rdata_len)
	{		{
	int result;		int result = 0;

	acpi_ec_write_cmd(ec, command);		acpi_ec_write_cmd(ec, command);

	for (; wdata_len > 0; wdata_len --) {		for (; wdata_len > 0; wdata_len --) {
	result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
	if (result)		if (result) {
	return result;		printk(KERN_ERR PREFIX "write_cmd timeout, command = %d\n",
			command);
			goto end;
			}
	acpi_ec_write_data(ec, *(wdata++));		acpi_ec_write_data(ec, *(wdata++));
	}		}

	if (!rdata_len) {		if (!rdata_len) {
	result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
	if (result)		if (result) {
	return result;		printk(KERN_ERR PREFIX "finish-write timeout, command = %d\n",
			command);
			goto end;
			}
	}		}

	for (; rdata_len > 0; rdata_len --) {		for (; rdata_len > 0; rdata_len --) {
	result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1);		result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1);
	if (result)		if (result) {
	return result;		printk(KERN_ERR PREFIX "read timeout, command = %d\n",
			command);
			goto end;
			}

	*(rdata++) = acpi_ec_read_data(ec);		*(rdata++) = acpi_ec_read_data(ec);
	}		}
			end:
	return 0;		return result;
	}		}

	static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,		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		Event Management
	-------------------------------------------------------------------------- */		-------------------------------------------------------------------------- */

	struct acpi_ec_query_data {
	acpi_handle handle;
	u8 data;
	};

	static void acpi_ec_gpe_query(void *ec_cxt)		static void acpi_ec_gpe_query(void *ec_cxt)
	{		{
	struct acpi_ec ec = (struct acpi_ec )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);		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);		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);		acpi_clear_gpe(NULL, ec->gpe_bit, ACPI_ISR);

	if (acpi_ec_mode == EC_INTR) {		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);		value = acpi_ec_read_status(ec);
	if (value & ACPI_EC_FLAG_SCI) {		if (value & ACPI_EC_FLAG_SCI) {
	status = acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query, ec);		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);		acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_ISR);
	return status == AE_OK ?		return status == AE_OK ?