From 6a084d6b3dc200b855ae8a3c6771abe285a3835d Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 21 May 2013 11:36:30 -0300 Subject: [PATCH] [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: kbuild test robot Acked-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/i2c/saa7115.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/drivers/media/i2c/saa7115.c b/drivers/media/i2c/saa7115.c index be32688797e1..8316ae448f4c 100644 --- a/drivers/media/i2c/saa7115.c +++ b/drivers/media/i2c/saa7115.c @@ -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", -- 2.39.5