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Commit 0b80a8ff authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

Merge branch 'acpi-ec' 

* acpi-ec:
  ACPI / EC: Free saved_ec on error exit path
  ACPI / EC: Add detailed fields debugging support of EC_SC(R).
  ACPI / EC: Update revision due to recent changes
  ACPI / EC: Fix race condition in ec_transaction_completed()
  ACPI / EC: Remove duplicated ec_wait_ibf0() waiter
  ACPI / EC: Add asynchronous command byte write support
  ACPI / EC: Avoid race condition related to advance_transaction()
parents 4488c99b ed4b197d

drivers/acpi/ec.c

+85 −79
Original line number Diff line number Diff line 
/*

 *  ec.c - ACPI Embedded Controller Driver (v2.1)

 *  ec.c - ACPI Embedded Controller Driver (v2.2)

 *

 *  Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@suse.de>

 *  Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>

 *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>

 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>

 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>

 *  Copyright (C) 2001-2014 Intel Corporation

 *    Author: 2014       Lv Zheng <lv.zheng@intel.com>

 *            2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>

 *            2006       Denis Sadykov <denis.m.sadykov@intel.com>

 *            2004       Luming Yu <luming.yu@intel.com>

 *            2001, 2002 Andy Grover <andrew.grover@intel.com>

 *            2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>

 *  Copyright (C) 2008      Alexey Starikovskiy <astarikovskiy@suse.de>

 *

 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 *
@@ -52,6 +55,7 @@ 
/* EC status register */

#define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */

#define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */

#define ACPI_EC_FLAG_CMD	0x08	/* Input buffer contains a command */

#define ACPI_EC_FLAG_BURST	0x10	/* burst mode */

#define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */
@@ -78,6 +82,9 @@ enum { 
	EC_FLAGS_BLOCKED,		/* Transactions are blocked */

};



#define ACPI_EC_COMMAND_POLL		0x01 /* Available for command byte */

#define ACPI_EC_COMMAND_COMPLETE	0x02 /* Completed last byte */



/* 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);
@@ -109,7 +116,7 @@ struct transaction { 
	u8 ri;

	u8 wlen;

	u8 rlen;

	bool done;

	u8 flags;

};



struct acpi_ec *boot_ec, *first_ec;
@@ -127,83 +134,104 @@ static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */ 
static inline u8 acpi_ec_read_status(struct acpi_ec *ec)

{

	u8 x = inb(ec->command_addr);

	pr_debug("---> status = 0x%2.2x\n", x);

	pr_debug("EC_SC(R) = 0x%2.2x "

		 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d\n",

		 x,

		 !!(x & ACPI_EC_FLAG_SCI),

		 !!(x & ACPI_EC_FLAG_BURST),

		 !!(x & ACPI_EC_FLAG_CMD),

		 !!(x & ACPI_EC_FLAG_IBF),

		 !!(x & ACPI_EC_FLAG_OBF));

	return x;

}



static inline u8 acpi_ec_read_data(struct acpi_ec *ec)

{

	u8 x = inb(ec->data_addr);

	pr_debug("---> data = 0x%2.2x\n", x);

	pr_debug("EC_DATA(R) = 0x%2.2x\n", x);

	return x;

}



static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)

{

	pr_debug("<--- command = 0x%2.2x\n", command);

	pr_debug("EC_SC(W) = 0x%2.2x\n", command);

	outb(command, ec->command_addr);

}



static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)

{

	pr_debug("<--- data = 0x%2.2x\n", data);

	pr_debug("EC_DATA(W) = 0x%2.2x\n", data);

	outb(data, ec->data_addr);

}



static int ec_transaction_done(struct acpi_ec *ec)

static int ec_transaction_completed(struct acpi_ec *ec)

{

	unsigned long flags;

	int ret = 0;

	spin_lock_irqsave(&ec->lock, flags);

	if (!ec->curr || ec->curr->done)

	if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))

		ret = 1;

	spin_unlock_irqrestore(&ec->lock, flags);

	return ret;

}



static void start_transaction(struct acpi_ec *ec)

{

	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;

	ec->curr->done = false;

	acpi_ec_write_cmd(ec, ec->curr->command);

}



static void advance_transaction(struct acpi_ec *ec, u8 status)

static bool advance_transaction(struct acpi_ec *ec)

{

	unsigned long flags;

	struct transaction *t;

	u8 status;

	bool wakeup = false;



	spin_lock_irqsave(&ec->lock, flags);

	pr_debug("===== %s =====\n", in_interrupt() ? "IRQ" : "TASK");

	status = acpi_ec_read_status(ec);

	t = ec->curr;

	if (!t)

		goto unlock;

		goto err;

	if (t->flags & ACPI_EC_COMMAND_POLL) {

		if (t->wlen > t->wi) {

			if ((status & ACPI_EC_FLAG_IBF) == 0)

			acpi_ec_write_data(ec,

				t->wdata[t->wi++]);

				acpi_ec_write_data(ec, t->wdata[t->wi++]);

			else

				goto err;

		} else if (t->rlen > t->ri) {

			if ((status & ACPI_EC_FLAG_OBF) == 1) {

				t->rdata[t->ri++] = acpi_ec_read_data(ec);

			if (t->rlen == t->ri)

				t->done = true;

				if (t->rlen == t->ri) {

					t->flags |= ACPI_EC_COMMAND_COMPLETE;

					wakeup = true;

				}

			} else

				goto err;

		} else if (t->wlen == t->wi &&

		   (status & ACPI_EC_FLAG_IBF) == 0)

		t->done = true;

	goto unlock;

			   (status & ACPI_EC_FLAG_IBF) == 0) {

			t->flags |= ACPI_EC_COMMAND_COMPLETE;

			wakeup = true;

		}

		return wakeup;

	} else {

		if ((status & ACPI_EC_FLAG_IBF) == 0) {

			acpi_ec_write_cmd(ec, t->command);

			t->flags |= ACPI_EC_COMMAND_POLL;

		} else

			goto err;

		return wakeup;

	}

err:

	/*

	 * If SCI bit is set, then don't think it's a false IRQ

	 * otherwise will take a not handled IRQ as a false one.

	 */

	if (in_interrupt() && !(status & ACPI_EC_FLAG_SCI))

	if (!(status & ACPI_EC_FLAG_SCI)) {

		if (in_interrupt() && t)

			++t->irq_count;

	}

	return wakeup;

}



unlock:

	spin_unlock_irqrestore(&ec->lock, flags);

static void start_transaction(struct acpi_ec *ec)

{

	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;

	ec->curr->flags = 0;

	(void)advance_transaction(ec);

}



static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
@@ -228,15 +256,17 @@ static int ec_poll(struct acpi_ec *ec) 
			/* don't sleep with disabled interrupts */

			if (EC_FLAGS_MSI || irqs_disabled()) {

				udelay(ACPI_EC_MSI_UDELAY);

				if (ec_transaction_done(ec))

				if (ec_transaction_completed(ec))

					return 0;

			} else {

				if (wait_event_timeout(ec->wait,

						ec_transaction_done(ec),

						ec_transaction_completed(ec),

						msecs_to_jiffies(1)))

					return 0;

			}

			advance_transaction(ec, acpi_ec_read_status(ec));

			spin_lock_irqsave(&ec->lock, flags);

			(void)advance_transaction(ec);

			spin_unlock_irqrestore(&ec->lock, flags);

		} while (time_before(jiffies, delay));

		pr_debug("controller reset, restart transaction\n");

		spin_lock_irqsave(&ec->lock, flags);
@@ -268,23 +298,6 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, 
	return ret;

}



static int ec_check_ibf0(struct acpi_ec *ec)

{

	u8 status = acpi_ec_read_status(ec);

	return (status & ACPI_EC_FLAG_IBF) == 0;

}



static int ec_wait_ibf0(struct acpi_ec *ec)

{

	unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);

	/* interrupt wait manually if GPE mode is not active */

	while (time_before(jiffies, delay))

		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),

					msecs_to_jiffies(1)))

			return 0;

	return -ETIME;

}



static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)

{

	int status;
@@ -305,12 +318,6 @@ static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t) 
			goto unlock;

		}

	}

	if (ec_wait_ibf0(ec)) {

		pr_err("input buffer is not empty, "

				"aborting transaction\n");

		status = -ETIME;

		goto end;

	}

	pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",

			t->command, t->wdata ? t->wdata[0] : 0);

	/* disable GPE during transaction if storm is detected */
@@ -334,7 +341,6 @@ static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t) 
		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);

	}

	pr_debug("transaction end\n");

end:

	if (ec->global_lock)

		acpi_release_global_lock(glk);

unlock:
@@ -634,17 +640,14 @@ static int ec_check_sci(struct acpi_ec *ec, u8 state) 
static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,

	u32 gpe_number, void *data)

{

	unsigned long flags;

	struct acpi_ec *ec = data;

	u8 status = acpi_ec_read_status(ec);



	pr_debug("~~~> interrupt, status:0x%02x\n", status);



	advance_transaction(ec, status);

	if (ec_transaction_done(ec) &&

	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {

	spin_lock_irqsave(&ec->lock, flags);

	if (advance_transaction(ec))

		wake_up(&ec->wait);

	spin_unlock_irqrestore(&ec->lock, flags);

	ec_check_sci(ec, acpi_ec_read_status(ec));

	}

	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;

}
@@ -1066,8 +1069,10 @@ int __init acpi_ec_ecdt_probe(void) 
	/* fall through */

	}



	if (EC_FLAGS_SKIP_DSDT_SCAN)

	if (EC_FLAGS_SKIP_DSDT_SCAN) {

		kfree(saved_ec);

		return -ENODEV;

	}



	/* This workaround is needed only on some broken machines,

	 * which require early EC, but fail to provide ECDT */
@@ -1105,6 +1110,7 @@ int __init acpi_ec_ecdt_probe(void) 
	}

error:

	kfree(boot_ec);

	kfree(saved_ec);

	boot_ec = NULL;

	return -ENODEV;

}