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Commit a0e92d70 authored by Jean Delvare's avatar Jean Delvare
Browse files

hwmon: (smsc47m1) Only request I/O ports we really use 



The I/O area of the SMSC LPC47M1xx chips which we use, gives access to
a lot of registers, some of which are related to fan speed monitoring
and control, but many are not. At the moment, the smsc47m1 driver
requests the whole I/O port range. This could easily result in
resource conflicts with either ACPI or other drivers.

Request only the I/O ports we really use, to prevent such conflicts.

Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
Tested-by: default avatarSean Fidler <fidlersean@gmail.com>
parent 3c57e89b

drivers/hwmon/smsc47m1.c

+89 −10
Original line number Diff line number Diff line
@@ -481,13 +481,94 @@ static int __init smsc47m1_find(unsigned short *addr, 
	return 0;

}



#define CHECK		1

#define REQUEST		2

#define RELEASE		3



/*

 * This function can be used to:

 *  - test for resource conflicts with ACPI

 *  - request the resources

 *  - release the resources

 * We only allocate the I/O ports we really need, to minimize the risk of

 * conflicts with ACPI or with other drivers.

 */

static int smsc47m1_handle_resources(unsigned short address, enum chips type,

				     int action, struct device *dev)

{

	static const u8 ports_m1[] = {

		/* register, region length */

		0x04, 1,

		0x33, 4,

		0x56, 7,

	};



	static const u8 ports_m2[] = {

		/* register, region length */

		0x04, 1,

		0x09, 1,

		0x2c, 2,

		0x35, 4,

		0x56, 7,

		0x69, 4,

	};



	int i, ports_size, err;

	const u8 *ports;



	switch (type) {

	case smsc47m1:

	default:

		ports = ports_m1;

		ports_size = ARRAY_SIZE(ports_m1);

		break;

	case smsc47m2:

		ports = ports_m2;

		ports_size = ARRAY_SIZE(ports_m2);

		break;

	}



	for (i = 0; i + 1 < ports_size; i += 2) {

		unsigned short start = address + ports[i];

		unsigned short len = ports[i + 1];



		switch (action) {

		case CHECK:

			/* Only check for conflicts */

			err = acpi_check_region(start, len, DRVNAME);

			if (err)

				return err;

			break;

		case REQUEST:

			/* Request the resources */

			if (!request_region(start, len, DRVNAME)) {

				dev_err(dev, "Region 0x%hx-0x%hx already in "

					"use!\n", start, start + len);



				/* Undo all requests */

				for (i -= 2; i >= 0; i -= 2)

					release_region(address + ports[i],

						       ports[i + 1]);

				return -EBUSY;

			}

			break;

		case RELEASE:

			/* Release the resources */

			release_region(start, len);

			break;

		}

	}



	return 0;

}



static int __devinit smsc47m1_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	struct smsc47m1_sio_data *sio_data = dev->platform_data;

	struct smsc47m1_data *data;

	struct resource *res;

	int err = 0;

	int err;

	int fan1, fan2, fan3, pwm1, pwm2, pwm3;



	static const char *names[] = {
@@ -496,12 +577,10 @@ static int __devinit smsc47m1_probe(struct platform_device *pdev) 
	};



	res = platform_get_resource(pdev, IORESOURCE_IO, 0);

	if (!request_region(res->start, SMSC_EXTENT, DRVNAME)) {

		dev_err(dev, "Region 0x%lx-0x%lx already in use!\n",

			(unsigned long)res->start,

			(unsigned long)res->end);

		return -EBUSY;

	}

	err = smsc47m1_handle_resources(res->start, sio_data->type,

					REQUEST, dev);

	if (err < 0)

		return err;



	if (!(data = kzalloc(sizeof(struct smsc47m1_data), GFP_KERNEL))) {

		err = -ENOMEM;
@@ -637,7 +716,7 @@ static int __devinit smsc47m1_probe(struct platform_device *pdev) 
	platform_set_drvdata(pdev, NULL);

	kfree(data);

error_release:

	release_region(res->start, SMSC_EXTENT);

	smsc47m1_handle_resources(res->start, sio_data->type, RELEASE, dev);

	return err;

}
@@ -650,7 +729,7 @@ static int __devexit smsc47m1_remove(struct platform_device *pdev) 
	sysfs_remove_group(&pdev->dev.kobj, &smsc47m1_group);



	res = platform_get_resource(pdev, IORESOURCE_IO, 0);

	release_region(res->start, SMSC_EXTENT);

	smsc47m1_handle_resources(res->start, data->type, RELEASE, &pdev->dev);

	platform_set_drvdata(pdev, NULL);

	kfree(data);
@@ -717,7 +796,7 @@ static int __init smsc47m1_device_add(unsigned short address, 
	};

	int err;



	err = acpi_check_resource_conflict(&res);

	err = smsc47m1_handle_resources(address, sio_data->type, CHECK, NULL);

	if (err)

		goto exit;