Hello Jacopo Mondi,
The patch 8004c91e2095: "media: i2c: ov5670: Use common clock
framework" from Jan 26, 2023, leads to the following Smatch static
checker warning:
drivers/media/i2c/ov5670.c:2670 ov5670_probe()
warn: passing zero to 'PTR_ERR'
drivers/media/i2c/ov5670.c
2648 static int ov5670_probe(struct i2c_client *client)
2649 {
2650 struct ov5670 *ov5670;
2651 const char *err_msg;
2652 u32 input_clk = 0;
2653 bool full_power;
2654 int ret;
2655
2656 ov5670 = devm_kzalloc(&client->dev, sizeof(*ov5670), GFP_KERNEL);
2657 if (!ov5670) {
2658 ret = -ENOMEM;
2659 err_msg = "devm_kzalloc() error";
2660 goto error_print;
2661 }
2662
2663 ov5670->xvclk = devm_clk_get(&client->dev, NULL);
2664 if (!IS_ERR_OR_NULL(ov5670->xvclk))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Imagine CONFIG_HAVE_CLK is not enabled so now devm_clk_get() returns
NULL.
2665 input_clk = clk_get_rate(ov5670->xvclk);
2666 else if (PTR_ERR(ov5670->xvclk) == -ENOENT)
2667 device_property_read_u32(&client->dev, "clock-frequency",
2668 &input_clk);
2669 else
--> 2670 return dev_err_probe(&client->dev, PTR_ERR(ov5670->xvclk),
2671 "error getting clock\n");
A NULL is zero and zero is success.
That means this code returns success without doing anything. Perhaps
the right thing is to use use Kconfig to ensure that this cannot be
build without CONFIG_HAVE_CLK. The other solution is to write the
driver with a bunch of NULL checks so that it still runs without a clk.
The IS_ERR_OR_NULL() check should be changed to if (IS_ERR()).
2672
2673 if (input_clk != OV5670_XVCLK_FREQ) {
2674 dev_err(&client->dev,
2675 "Unsupported clock frequency %u\n", input_clk);
2676 return -EINVAL;
2677 }
2678
2679 /* Initialize subdev */
2680 v4l2_i2c_subdev_init(&ov5670->sd, client, &ov5670_subdev_ops);
2681
2682 ret = ov5670_regulators_probe(ov5670);
2683 if (ret) {
2684 err_msg = "Regulators probe failed";
regards,
dan carpenter
