Commit 6a084d6b authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

[media] saa7115: Don't use a dynamic array 



At least on s390, gcc complains about that:
    drivers/media/i2c/saa7115.c: In function 'saa711x_detect_chip.constprop.2':
    drivers/media/i2c/saa7115.c:1647:1: warning: 'saa711x_detect_chip.constprop.2' uses dynamic stack allocation [enabled by default]

While for me the above report seems utterly bogus, as the
compiler should be optimizing saa711x_detect_chip, merging
it with saa711x_detect_chip and changing:
	char chip_ver[size - 1];
to
	char chip_ver[16];

because this function is only called on this code snippet:
	char name[17];
	...
	ident = saa711x_detect_chip(client, id, name, sizeof(name));

It seems that gcc is not optimizing it, at least on s390.

As getting rid of it is easy, let's do it.

Reported-by: default avatarkbuild test robot <fengguang.wu@intel.com>
Acked-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 2a848b2c

drivers/media/i2c/saa7115.c

+10 −9
Original line number Diff line number Diff line
@@ -1602,6 +1602,8 @@ static const struct v4l2_subdev_ops saa711x_ops = { 
	.vbi = &saa711x_vbi_ops,

};



#define CHIP_VER_SIZE	16



/* ----------------------------------------------------------------------- */



/**
@@ -1609,7 +1611,6 @@ static const struct v4l2_subdev_ops saa711x_ops = { 
 * @client:		I2C client structure.

 * @id:			I2C device ID structure.

 * @name:		Name of the device to be filled.

 * @size:		Size of the name var.

 *

 * Detects the Philips/NXP saa711x chip, or some clone of it.

 * if 'id' is NULL or id->driver_data is equal to 1, it auto-probes
@@ -1621,9 +1622,9 @@ static const struct v4l2_subdev_ops saa711x_ops = { 
 */

static int saa711x_detect_chip(struct i2c_client *client,

			       const struct i2c_device_id *id,

			       char *name, unsigned size)

			       char *name)

{

	char chip_ver[size - 1];

	char chip_ver[CHIP_VER_SIZE];

	char chip_id;

	int i;

	int autodetect;
@@ -1631,7 +1632,7 @@ static int saa711x_detect_chip(struct i2c_client *client, 
	autodetect = !id || id->driver_data == 1;



	/* Read the chip version register */

	for (i = 0; i < size - 1; i++) {

	for (i = 0; i < CHIP_VER_SIZE; i++) {

		i2c_smbus_write_byte_data(client, 0, i);

		chip_ver[i] = i2c_smbus_read_byte_data(client, 0);

		name[i] = (chip_ver[i] & 0x0f) + '0';
@@ -1643,7 +1644,7 @@ static int saa711x_detect_chip(struct i2c_client *client, 
	/* Check if it is a Philips/NXP chip */

	if (!memcmp(name + 1, "f711", 4)) {

		chip_id = name[5];

		snprintf(name, size, "saa711%c", chip_id);

		snprintf(name, CHIP_VER_SIZE, "saa711%c", chip_id);



		if (!autodetect && strcmp(name, id->name))

			return -EINVAL;
@@ -1651,7 +1652,7 @@ static int saa711x_detect_chip(struct i2c_client *client, 
		switch (chip_id) {

		case '1':

			if (chip_ver[0] & 0xf0) {

				snprintf(name, size, "saa711%ca", chip_id);

				snprintf(name, CHIP_VER_SIZE, "saa711%ca", chip_id);

				v4l_info(client, "saa7111a variant found\n");

				return V4L2_IDENT_SAA7111A;

			}
@@ -1689,7 +1690,7 @@ static int saa711x_detect_chip(struct i2c_client *client, 
		 * the lower nibble is a gm7113c.

		 */



		strlcpy(name, "gm7113c", size);

		strlcpy(name, "gm7113c", CHIP_VER_SIZE);



		if (!autodetect && strcmp(name, id->name))

			return -EINVAL;
@@ -1714,13 +1715,13 @@ static int saa711x_probe(struct i2c_client *client, 
	struct v4l2_subdev *sd;

	struct v4l2_ctrl_handler *hdl;

	int ident;

	char name[17];

	char name[CHIP_VER_SIZE + 1];



	/* Check if the adapter supports the needed features */

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))

		return -EIO;



	ident = saa711x_detect_chip(client, id, name, sizeof(name));

	ident = saa711x_detect_chip(client, id, name);

	if (ident == -EINVAL) {

		/* Chip exists, but doesn't match */

		v4l_warn(client, "found %s while %s was expected\n",

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