ACPI: ec: Remove expect_event and all races around it. (af3fd140) · Commits · e / devices / android_kernel_samsung_universal8895

drivers/acpi/ec.c

+38 −46

Original line number	Diff line number	Diff line
		@@ -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) {
		int i;
		for (i = 0; i < ACPI_EC_UDELAY_COUNT; ++i) {
		if (acpi_ec_check_status(ec, event))
		return 0;
		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 (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);
		}
		}
		if (acpi_ec_check_status(ec, event)) {
		ec->expect_event = 0;
		return 0;
		}
		} 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);
		}
		}

		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 ?