Commit 5ce6185c authored by Finn Thain's avatar Finn Thain Committed by Michael Ellerman
Browse files

macintosh/via-macii: Simplify locking 



Modifying the request queue or changing the current state requires
mutual exclusion. Use local_irq_disable() consistently for this
rather than disabling the ADB interrupt. This simplifies the locking
scheme and brings via-macii into line with the other ADB drivers.

Tested-by: default avatarStan Johnson <userm57@yahoo.com>
Signed-off-by: default avatarFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 5f93d708

drivers/macintosh/via-macii.c

+18 −8
Original line number Original line Diff line number Diff line
@@ -216,22 +216,23 @@ static void macii_queue_poll(void) 
static int macii_send_request(struct adb_request *req, int sync)

static int macii_send_request(struct adb_request *req, int sync)

{

{

	int err;

	int err;

	unsigned long flags;





	local_irq_save(flags);

	err = macii_write(req);

	err = macii_write(req);

	local_irq_restore(flags);

	if (err)

		return err;





	if (!err && sync)

	if (sync)

		while (!req->complete)

		while (!req->complete)

			macii_poll();

			macii_poll();





	return err;

	return 0;

}

}





/* Send an ADB request (append to request queue) */

/* Send an ADB request (append to request queue) */

static int macii_write(struct adb_request *req)

static int macii_write(struct adb_request *req)

{

{

	unsigned long flags;



	if (req->nbytes < 2 || req->data[0] != ADB_PACKET || req->nbytes > 15) {

	if (req->nbytes < 2 || req->data[0] != ADB_PACKET || req->nbytes > 15) {

		req->complete = 1;

		req->complete = 1;

		return -EINVAL;

		return -EINVAL;
@@ -242,6 +243,8 @@ static int macii_write(struct adb_request *req) 
	req->complete = 0;

	req->complete = 0;

	req->reply_len = 0;

	req->reply_len = 0;





	local_irq_save(flags);



	if (current_req != NULL) {

	if (current_req != NULL) {

		last_req->next = req;

		last_req->next = req;

		last_req = req;

		last_req = req;
@@ -250,6 +253,9 @@ static int macii_write(struct adb_request *req) 
		last_req = req;

		last_req = req;

		if (macii_state == idle) macii_start();

		if (macii_state == idle) macii_start();

	}

	}



	local_irq_restore(flags);



	return 0;

	return 0;

}

}
@@ -293,9 +299,7 @@ static inline int need_autopoll(void) { 
/* Prod the chip without interrupts */

/* Prod the chip without interrupts */

static void macii_poll(void)

static void macii_poll(void)

{

{

	disable_irq(IRQ_MAC_ADB);

	macii_interrupt(0, NULL);

	macii_interrupt(0, NULL);

	enable_irq(IRQ_MAC_ADB);

}

}





/* Reset the bus */

/* Reset the bus */
@@ -358,14 +362,19 @@ static irqreturn_t macii_interrupt(int irq, void *arg) 
{

{

	int x;

	int x;

	struct adb_request *req;

	struct adb_request *req;

	unsigned long flags;



	local_irq_save(flags);





	if (!arg) {

	if (!arg) {

		/* Clear the SR IRQ flag when polling. */

		/* Clear the SR IRQ flag when polling. */

		if (via[IFR] & SR_INT)

		if (via[IFR] & SR_INT)

			via[IFR] = SR_INT;

			via[IFR] = SR_INT;

		else

		else {

			local_irq_restore(flags);

			return IRQ_NONE;

			return IRQ_NONE;

		}

		}

	}





	last_status = status;

	last_status = status;

	status = via[B] & (ST_MASK|CTLR_IRQ);

	status = via[B] & (ST_MASK|CTLR_IRQ);
@@ -512,5 +521,6 @@ static irqreturn_t macii_interrupt(int irq, void *arg) 
		break;

		break;

	}

	}





	local_irq_restore(flags);

	return IRQ_HANDLED;

	return IRQ_HANDLED;

}
 
}

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