[bug report] mfd: lp87565: Handle optional reset pin

Dan Carpenter
2021-11-17T11:17:23Z

Hello Luca Ceresoli,

The patch 50e4d7a2a667: "mfd: lp87565: Handle optional reset pin"
from Feb 26, 2021, leads to the following Smatch static checker
warning:

drivers/mfd/lp87565.c:76 lp87565_probe()
warn: 'lp87565->reset_gpio' could be an error pointer

drivers/mfd/lp87565.c
46 static int lp87565_probe(struct i2c_client *client,
47 const struct i2c_device_id *ids)
48 {
49 struct lp87565 *lp87565;
50 const struct of_device_id *of_id;
51 int ret;
52 unsigned int otpid;
53
54 lp87565 = devm_kzalloc(&client->dev, sizeof(*lp87565), GFP_KERNEL);
55 if (!lp87565)
56 return -ENOMEM;
57
58 lp87565->dev = &client->dev;
59
60 lp87565->regmap = devm_regmap_init_i2c(client, &lp87565_regmap_config);
61 if (IS_ERR(lp87565->regmap)) {
62 ret = PTR_ERR(lp87565->regmap);
63 dev_err(lp87565->dev,
64 "Failed to initialize register map: %d\n", ret);
65 return ret;
66 }
67
68 lp87565->reset_gpio = devm_gpiod_get_optional(lp87565->dev, "reset",
69 GPIOD_OUT_LOW);
70 if (IS_ERR(lp87565->reset_gpio)) {
71 ret = PTR_ERR(lp87565->reset_gpio);
72 if (ret == -EPROBE_DEFER)
73 return ret;

Only "ret = -EPROBE_DEFER" is handled. Other error pointer will lead to
a crash.

74 }
75
--> 76 if (lp87565->reset_gpio) {
77 gpiod_set_value_cansleep(lp87565->reset_gpio, 1);
78 /* The minimum assertion time is undocumented, just guess */
79 usleep_range(2000, 4000);
80
81 gpiod_set_value_cansleep(lp87565->reset_gpio, 0);
82 /* Min 1.2 ms before first I2C transaction */
83 usleep_range(1500, 3000);
84 }
85
86 ret = regmap_read(lp87565->regmap, LP87565_REG_OTP_REV, &otpid);
87 if (ret) {
88 dev_err(lp87565->dev, "Failed to read OTP ID\n");
89 return ret;
90 }
91
92 lp87565->rev = otpid & LP87565_OTP_REV_OTP_ID;
93
94 of_id = of_match_device(of_lp87565_match_table, &client->dev);
95 if (of_id)
96 lp87565->dev_type = (enum lp87565_device_type)of_id->data;
97
98 i2c_set_clientdata(client, lp87565);
99
100 return devm_mfd_add_devices(lp87565->dev, PLATFORM_DEVID_AUTO,
101 lp87565_cells, ARRAY_SIZE(lp87565_cells),
102 NULL, 0, NULL);
103 }

regards,
dan carpenter