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[PATCHv2,12/29] s5h1420: Don't use dynamic static allocation

Message ID 1383399097-11615-13-git-send-email-m.chehab@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Mauro Carvalho Chehab Nov. 2, 2013, 1:31 p.m. UTC
Dynamic static allocation is evil, as Kernel stack is too low, and
compilation complains about it on some archs:

	drivers/media/dvb-frontends/s5h1420.c:851:1: warning: 's5h1420_tuner_i2c_tuner_xfer' uses dynamic stack allocation [enabled by default]

Instead, let's enforce a limit for the buffer.

In the specific case of this frontend, only ttpci uses it. The maximum
number of messages there is two, on I2C read operations. As the logic
can add an extra operation, change the size to 3.

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: Patrick Boettcher <pb@linuxtv.org>
---
 drivers/media/dvb-frontends/s5h1420.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)
diff mbox

Patch

diff --git a/drivers/media/dvb-frontends/s5h1420.c b/drivers/media/dvb-frontends/s5h1420.c
index e2fec9ebf947..e0b0366ccfa5 100644
--- a/drivers/media/dvb-frontends/s5h1420.c
+++ b/drivers/media/dvb-frontends/s5h1420.c
@@ -836,9 +836,16 @@  static u32 s5h1420_tuner_i2c_func(struct i2c_adapter *adapter)
 static int s5h1420_tuner_i2c_tuner_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msg[], int num)
 {
 	struct s5h1420_state *state = i2c_get_adapdata(i2c_adap);
-	struct i2c_msg m[1 + num];
+	struct i2c_msg m[3];
 	u8 tx_open[2] = { CON_1, state->CON_1_val | 1 }; /* repeater stops once there was a stop condition */
 
+	if (1 + num > ARRAY_SIZE(m)) {
+		printk(KERN_WARNING
+		       "%s: i2c xfer: num=%d is too big!\n",
+		       KBUILD_MODNAME, num);
+		return  -EREMOTEIO;
+	}
+
 	memset(m, 0, sizeof(struct i2c_msg) * (1 + num));
 
 	m[0].addr = state->config->demod_address;