[bug report] ASoC: Add support for Loongson I2S controller

[Dan Carpenter <dan.carpenter@xxxxxxxxxx>]

Hello Yingkun Meng,

Commit d84881e06836 ("ASoC: Add support for Loongson I2S controller")
from Jun 15, 2023 (linux-next), leads to the following Smatch static
checker warning:

	sound/soc/loongson/loongson_i2s_pci.c:131 loongson_i2s_pci_probe()
	error: 'i2s->regmap' dereferencing possible ERR_PTR()

sound/soc/loongson/loongson_i2s_pci.c
    73 static int loongson_i2s_pci_probe(struct pci_dev *pdev,
    74                                   const struct pci_device_id *pid)
    75 {
    76         const struct fwnode_handle *fwnode = pdev->dev.fwnode;
    77         struct loongson_dma_data *tx_data, *rx_data;
    78         struct device *dev = &pdev->dev;
    79         struct loongson_i2s *i2s;
    80         int ret;
    81 
    82         if (pcim_enable_device(pdev)) {
    83                 dev_err(dev, "pci_enable_device failed\n");
    84                 return -ENODEV;
    85         }
    86 
    87         i2s = devm_kzalloc(dev, sizeof(*i2s), GFP_KERNEL);
    88         if (!i2s)
    89                 return -ENOMEM;
    90 
    91         i2s->rev_id = pdev->revision;
    92         i2s->dev = dev;
    93         pci_set_drvdata(pdev, i2s);
    94 
    95         ret = pcim_iomap_regions(pdev, 1 << 0, dev_name(dev));
    96         if (ret < 0) {
    97                 dev_err(dev, "iomap_regions failed\n");
    98                 return ret;
    99         }
    100 
    101         i2s->reg_base = pcim_iomap_table(pdev)[0];
    102         i2s->regmap = devm_regmap_init_mmio(dev, i2s->reg_base,
    103                                             &loongson_i2s_regmap_config);
    104         if (IS_ERR(i2s->regmap))
    105                 dev_err_probe(dev, PTR_ERR(i2s->regmap), "regmap_init_mmio failed\n");

return dev_err_probe()?

    106 
    107         tx_data = &i2s->tx_dma_data;
    108         rx_data = &i2s->rx_dma_data;
    109 
    110         tx_data->dev_addr = pci_resource_start(pdev, 0) + LS_I2S_TX_DATA;
    111         tx_data->order_addr = i2s->reg_base + LS_I2S_TX_ORDER;
    112 
    113         rx_data->dev_addr = pci_resource_start(pdev, 0) + LS_I2S_RX_DATA;
    114         rx_data->order_addr = i2s->reg_base + LS_I2S_RX_ORDER;
    115 
    116         tx_data->irq = fwnode_irq_get_byname(fwnode, "tx");
    117         if (tx_data->irq < 0)
    118                 dev_err_probe(dev, tx_data->irq, "dma tx irq invalid\n");
    119 
    120         rx_data->irq = fwnode_irq_get_byname(fwnode, "rx");
    121         if (rx_data->irq < 0)
    122                 dev_err_probe(dev, rx_data->irq, "dma rx irq invalid\n");
    123 
    124         ret = device_property_read_u32(dev, "clock-frequency", &i2s->clk_rate);
    125         if (ret)
    126                 dev_err_probe(dev, ret, "clock-frequency property invalid\n");
    127 
    128         dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
    129 
    130         if (i2s->rev_id == 1) {
--> 131                 regmap_write(i2s->regmap, LS_I2S_CTRL, I2S_CTRL_RESET);
                                     ^^^^^^^^^^^^

    132                 udelay(200);
    133         }
    134 
    135         ret = devm_snd_soc_register_component(dev, &loongson_i2s_component,
    136                                               &loongson_i2s_dai, 1);
    137         if (ret)
    138                 dev_err_probe(dev, ret, "register DAI failed\n");

Same.  Seems like a missing return statement.

    139 
    140         return 0;
    141 }

regards,
dan carpenter