[PATCH 3/4] [media] cx231xx-i2c: reduce stack size in bus scan

From: Arnd Bergmann
Date: Thu Feb 02 2017 - 09:53:59 EST


The cx231xx_do_i2c_scan function needs a lot of stack because
it puts an i2c_client structure on it:

drivers/media/usb/cx231xx/cx231xx-i2c.c: In function 'cx231xx_do_i2c_scan':
drivers/media/usb/cx231xx/cx231xx-i2c.c:518:1: error: the frame size of 1248 bytes is larger than 1152 bytes [-Werror=frame-larger-than=]

This changes it to call i2c_transfer() directly instead, avoiding the
need for the structure.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/media/usb/cx231xx/cx231xx-i2c.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/media/usb/cx231xx/cx231xx-i2c.c b/drivers/media/usb/cx231xx/cx231xx-i2c.c
index 35e9acfe63d3..24e23a06d8c6 100644
--- a/drivers/media/usb/cx231xx/cx231xx-i2c.c
+++ b/drivers/media/usb/cx231xx/cx231xx-i2c.c
@@ -491,20 +491,24 @@ void cx231xx_do_i2c_scan(struct cx231xx *dev, int i2c_port)
{
unsigned char buf;
int i, rc;
- struct i2c_client client;
+ struct i2c_adapter *adap;
+ struct i2c_msg msg = {
+ .flags = I2C_M_RD,
+ .len = 1,
+ .buf = &buf,
+ };

if (!i2c_scan)
return;

/* Don't generate I2C errors during scan */
dev->i2c_scan_running = true;
-
- memset(&client, 0, sizeof(client));
- client.adapter = cx231xx_get_i2c_adap(dev, i2c_port);
+ adap = cx231xx_get_i2c_adap(dev, i2c_port);

for (i = 0; i < 128; i++) {
- client.addr = i;
- rc = i2c_master_recv(&client, &buf, 0);
+ msg.addr = i;
+ rc = i2c_transfer(adap, &msg, 1);
+
if (rc < 0)
continue;
dev_info(dev->dev,
--
2.9.0