Commit be052cc8 authored by Roger Quadros's avatar Roger Quadros Committed by Chanwoo Choi
Browse files

extcon: Fix hang and extcon_get/set_cable_state(). 



Users of find_cable_index_by_name() will cause a kernel hang
as the while loop counter is never incremented and end condition
is never reached.

extcon_get_cable_state() and extcon_set_cable_state() are broken
because they use cable index instead of cable id. This causes
the first cable state (cable.0) to be always invalid in sysfs
or extcon_get_cable_state() users.

Introduce a new function find_cable_id_by_name() that fixes
both of the above issues.

Fixes: commit 73b6ecdb ("extcon: Redefine the unique id of supported external connectors without 'enum extcon' type")
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarRoger Quadros <rogerq@ti.com>
Tested-by: default avatarIvan T. Ivanov <ivan.ivanov@linaro.org>
[cw00.choi: Fix minor coding style]
Signed-off-by: default avatarChanwoo Choi <cw00.choi@samsung.com>
parent e350f804

drivers/extcon/extcon.c

+34 −12
Original line number Diff line number Diff line
@@ -124,25 +124,35 @@ static int find_cable_index_by_id(struct extcon_dev *edev, const unsigned int id 
	return -EINVAL;

}



static int find_cable_index_by_name(struct extcon_dev *edev, const char *name)

static int find_cable_id_by_name(struct extcon_dev *edev, const char *name)

{

	unsigned int id = EXTCON_NONE;

	unsigned int id = -EINVAL;

	int i = 0;



	if (edev->max_supported == 0)

		return -EINVAL;



	/* Find the the number of extcon cable */

	/* Find the id of extcon cable */

	while (extcon_name[i]) {

		if (!strncmp(extcon_name[i], name, CABLE_NAME_MAX)) {

			id = i;

			break;

		}

		i++;

	}



	if (id == EXTCON_NONE)

	return id;

}



static int find_cable_index_by_name(struct extcon_dev *edev, const char *name)

{

	unsigned int id;



	if (edev->max_supported == 0)

		return -EINVAL;



	/* Find the the number of extcon cable */

	id = find_cable_id_by_name(edev, name);

	if (id < 0)

		return id;



	return find_cable_index_by_id(edev, id);

}
@@ -228,9 +238,11 @@ static ssize_t cable_state_show(struct device *dev, 
	struct extcon_cable *cable = container_of(attr, struct extcon_cable,

						  attr_state);



	int i = cable->cable_index;



	return sprintf(buf, "%d\n",

		       extcon_get_cable_state_(cable->edev,

					       cable->cable_index));

					       cable->edev->supported_cable[i]));

}



/**
@@ -361,8 +373,13 @@ EXPORT_SYMBOL_GPL(extcon_get_cable_state_); 
 */

int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)

{

	return extcon_get_cable_state_(edev, find_cable_index_by_name

						(edev, cable_name));

	unsigned int id;



	id = find_cable_id_by_name(edev, cable_name);

	if (id < 0)

		return id;



	return extcon_get_cable_state_(edev, id);

}

EXPORT_SYMBOL_GPL(extcon_get_cable_state);
@@ -404,8 +421,13 @@ EXPORT_SYMBOL_GPL(extcon_set_cable_state_); 
int extcon_set_cable_state(struct extcon_dev *edev,

			const char *cable_name, bool cable_state)

{

	return extcon_set_cable_state_(edev, find_cable_index_by_name

					(edev, cable_name), cable_state);

	unsigned int id;



	id = find_cable_id_by_name(edev, cable_name);

	if (id < 0)

		return id;



	return extcon_set_cable_state_(edev, id, cable_state);

}

EXPORT_SYMBOL_GPL(extcon_set_cable_state);

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