[bug report] platform/mellanox: mlxreg-dpu: Add initial support for Nvidia DPU

[Dan Carpenter <dan.carpenter@linaro.org>]

Hello Vadim Pasternak,

Commit 3e75f2954116 ("platform/mellanox: mlxreg-dpu: Add initial
support for Nvidia DPU") from Apr 21, 2025 (linux-next), leads to the
following Smatch static checker warning:

    drivers/platform/mellanox/mlxreg-dpu.c:539 mlxreg_dpu_probe()
    warn: refcount leak 'data->hpdev.adapter->dev.kobj.kref.refcount.refs.counter': lines='539'

    drivers/platform/mellanox/mlxreg-dpu.c:565 mlxreg_dpu_probe()
    warn: passing a valid pointer to 'PTR_ERR'

drivers/platform/mellanox/mlxreg-dpu.c
    522 static int mlxreg_dpu_probe(struct platform_device *pdev)
    523 {
    524         struct mlxreg_core_data *data;
    525         struct mlxreg_dpu *mlxreg_dpu;
    526         void *regmap;
    527         int err;
    528 
    529         data = dev_get_platdata(&pdev->dev);
    530         if (!data || !data->hpdev.brdinfo)
    531                 return -EINVAL;
    532 
    533         data->hpdev.adapter = i2c_get_adapter(data->hpdev.nr);
    534         if (!data->hpdev.adapter)
    535                 return -EPROBE_DEFER;

This should call i2c_put_adapter() before returning.

    536 
    537         mlxreg_dpu = devm_kzalloc(&pdev->dev, sizeof(*mlxreg_dpu), GFP_KERNEL);
    538         if (!mlxreg_dpu)
    539                 return -ENOMEM;
    540 
    541         /* Create device at the top of DPU I2C tree. */
    542         data->hpdev.client = i2c_new_client_device(data->hpdev.adapter,
    543                                                    data->hpdev.brdinfo);
    544         if (IS_ERR(data->hpdev.client)) {
    545                 dev_err(&pdev->dev, "Failed to create client %s at bus %d at addr 0x%02x\n",
    546                         data->hpdev.brdinfo->type, data->hpdev.nr, data->hpdev.brdinfo->addr);
    547                 err = PTR_ERR(data->hpdev.client);
    548                 goto i2c_new_device_fail;
    549         }
    550 
    551         regmap = devm_regmap_init_i2c(data->hpdev.client, &mlxreg_dpu_regmap_conf);
    552         if (IS_ERR(regmap)) {
    553                 dev_err(&pdev->dev, "Failed to create regmap for client %s at bus %d at addr 0x%02x\n",
    554                         data->hpdev.brdinfo->type, data->hpdev.nr, data->hpdev.brdinfo->addr);
    555                 err = PTR_ERR(regmap);
    556                 goto devm_regmap_init_i2c_fail;
    557         }
    558 
    559         /* Sync registers with hardware. */
    560         regcache_mark_dirty(regmap);
    561         err = regcache_sync(regmap);
    562         if (err) {
    563                 dev_err(&pdev->dev, "Failed to sync regmap for client %s at bus %d at addr 0x%02x\n",
    564                         data->hpdev.brdinfo->type, data->hpdev.nr, data->hpdev.brdinfo->addr);
--> 565                 err = PTR_ERR(regmap);

Copy and paste.  "err" was already an error code.  Delete this line.

    566                 goto regcache_sync_fail;
    567         }
    568 
    569         mlxreg_dpu->data = data;
    570         mlxreg_dpu->dev = &pdev->dev;
    571         platform_set_drvdata(pdev, mlxreg_dpu);
    572 
    573         err = mlxreg_dpu_config_init(mlxreg_dpu, regmap, data, data->hpdev.brdinfo->irq);
    574         if (err)
    575                 goto mlxreg_dpu_config_init_fail;
    576 
    577         return err;
    578 
    579 mlxreg_dpu_config_init_fail:
    580 regcache_sync_fail:
    581 devm_regmap_init_i2c_fail:

I would really encourage people to use names which reflect what
the fuction or goto does instead of where the function is called from
etc.

err_unregister:

    582         i2c_unregister_device(data->hpdev.client);
    583 i2c_new_device_fail:

err_i2c_put:

    584         i2c_put_adapter(data->hpdev.adapter);
    585         return err;
    586 }

regards,
dan carpenter