[PATCH v2] media: tuner: add error handling for I2C transfers in set_type()

[PATCH v2] media: tuner: add error handling for I2C transfers in set_type()

[Wenyuan Li]

In set_type(), multiple I2C transfers are performed to initialize
certain tuners (FMD1216ME, FMD1216MEX, TD1316). However, the return
values of i2c_master_send() are not checked.

If any of these I2C transfers fail, the tuner initialization may be
incomplete, leading to incorrect device state or silent failures.

Fix this by:
- Adding a helper function tuner_i2c_send() that checks the return
  value of i2c_master_send() and logs errors with %pe format
- Replacing direct i2c_master_send() calls with tuner_i2c_send()
- Propagating errors to the attach_failed path

This ensures that I2C communication failures during tuner
initialization are properly detected and handled.

Cc: Markus <markus@example.com>
Signed-off-by: Wenyuan Li <2063309626@qq.com>
---
 drivers/media/v4l2-core/tuner-core.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/media/v4l2-core/tuner-core.c b/drivers/media/v4l2-core/tuner-core.c
index 004ec4d7beea..01f28436a1f8 100644
--- a/drivers/media/v4l2-core/tuner-core.c
+++ b/drivers/media/v4l2-core/tuner-core.c
@@ -280,6 +280,19 @@ static const struct analog_demod_ops tuner_analog_ops = {
  * Functions to select between radio and TV and tuner probe/remove functions
  */
 
+static int tuner_i2c_send(struct i2c_client *c, u8 *buf, int len)
+{
+	int ret = i2c_master_send(c, buf, len);
+
+	if (ret != len) {
+		int err = ret < 0 ? ret : -EIO;
+
+		dev_err(&c->dev, "I2C send failed: %pe\n", ERR_PTR(err));
+		return err;
+	}
+	return 0;
+}
+
 /**
  * set_type - Sets the tuner type for a given device
  *
@@ -351,11 +364,13 @@ static void set_type(struct i2c_client *c, unsigned int type,
 		buffer[1] = 0xdc;
 		buffer[2] = 0x9c;
 		buffer[3] = 0x60;
-		i2c_master_send(c, buffer, 4);
+		if (tuner_i2c_send(c, buffer, 4))
+			goto attach_failed;
 		mdelay(1);
 		buffer[2] = 0x86;
 		buffer[3] = 0x54;
-		i2c_master_send(c, buffer, 4);
+		if (tuner_i2c_send(c, buffer, 4))
+			goto attach_failed;
 		if (!dvb_attach(simple_tuner_attach, &t->fe,
 				t->i2c->adapter, t->i2c->addr, t->type))
 			goto attach_failed;
@@ -365,7 +380,8 @@ static void set_type(struct i2c_client *c, unsigned int type,
 		buffer[1] = 0xdc;
 		buffer[2] = 0x86;
 		buffer[3] = 0xa4;
-		i2c_master_send(c, buffer, 4);
+		if (tuner_i2c_send(c, buffer, 4))
+			goto attach_failed;
 		if (!dvb_attach(simple_tuner_attach, &t->fe,
 				t->i2c->adapter, t->i2c->addr, t->type))
 			goto attach_failed;
-- 
2.43.0

[PATCH v2] media: tuner: add error handling for I2C transfers in set_type()

[Wenyuan Li]

In set_type(), multiple I2C transfers are performed to initialize
certain tuners (FMD1216ME, FMD1216MEX, TD1316). However, the return
values of i2c_master_send() are not checked.

If any of these I2C transfers fail, the tuner initialization may be
incomplete, leading to incorrect device state or silent failures.

Fix this by:
- Adding a helper function tuner_i2c_send() that checks the return
  value of i2c_master_send() and logs errors with %pe format
- Replacing direct i2c_master_send() calls with tuner_i2c_send()
- Propagating errors to the attach_failed path

This ensures that I2C communication failures during tuner
initialization are properly detected and handled.

Cc: Markus <Markus.Elfring@web.de>
Signed-off-by: Wenyuan Li <2063309626@qq.com>
---
 drivers/media/v4l2-core/tuner-core.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/media/v4l2-core/tuner-core.c b/drivers/media/v4l2-core/tuner-core.c
index 004ec4d7beea..01f28436a1f8 100644
--- a/drivers/media/v4l2-core/tuner-core.c
+++ b/drivers/media/v4l2-core/tuner-core.c
@@ -280,6 +280,19 @@ static const struct analog_demod_ops tuner_analog_ops = {
  * Functions to select between radio and TV and tuner probe/remove functions
  */
 
+static int tuner_i2c_send(struct i2c_client *c, u8 *buf, int len)
+{
+	int ret = i2c_master_send(c, buf, len);
+
+	if (ret != len) {
+		int err = ret < 0 ? ret : -EIO;
+
+		dev_err(&c->dev, "I2C send failed: %pe\n", ERR_PTR(err));
+		return err;
+	}
+	return 0;
+}
+
 /**
  * set_type - Sets the tuner type for a given device
  *
@@ -351,11 +364,13 @@ static void set_type(struct i2c_client *c, unsigned int type,
 		buffer[1] = 0xdc;
 		buffer[2] = 0x9c;
 		buffer[3] = 0x60;
-		i2c_master_send(c, buffer, 4);
+		if (tuner_i2c_send(c, buffer, 4))
+			goto attach_failed;
 		mdelay(1);
 		buffer[2] = 0x86;
 		buffer[3] = 0x54;
-		i2c_master_send(c, buffer, 4);
+		if (tuner_i2c_send(c, buffer, 4))
+			goto attach_failed;
 		if (!dvb_attach(simple_tuner_attach, &t->fe,
 				t->i2c->adapter, t->i2c->addr, t->type))
 			goto attach_failed;
@@ -365,7 +380,8 @@ static void set_type(struct i2c_client *c, unsigned int type,
 		buffer[1] = 0xdc;
 		buffer[2] = 0x86;
 		buffer[3] = 0xa4;
-		i2c_master_send(c, buffer, 4);
+		if (tuner_i2c_send(c, buffer, 4))
+			goto attach_failed;
 		if (!dvb_attach(simple_tuner_attach, &t->fe,
 				t->i2c->adapter, t->i2c->addr, t->type))
 			goto attach_failed;
-- 
2.43.0

Re: [PATCH v2] media: tuner: add error handling for I2C transfers in set_type()

[Markus Elfring]

…
> This ensures that I2C communication failures during tuner
> initialization are properly detected and handled.

Were any source code analysis tools involved here?


Do any contributors care more for another development requirement?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v7.0-rc5#n94


> Cc: Markus <Markus.Elfring@web.de>

I would find other tag variants more helpful.

See also:
* https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v7.0-rc5#n145
* https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/stable-kernel-rules.rst?h=v7.0-rc5#n34

Regards,
Markus