On Fri, Sep 24, 2021 at 02:31:57PM -0700, David E. Box wrote:
Quick review:
> +static int sdsi_probe(struct platform_device *pdev)
> +{
> + void __iomem *disc_addr;
> + struct sdsi_priv *priv;
> + int ret;
> +
> + disc_addr = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(disc_addr))
> + return PTR_ERR(disc_addr);
> +
> + priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + kref_init(&priv->kref);
> +
> + platform_set_drvdata(pdev, priv);
> + priv->pdev = pdev;
> + mutex_init(&priv->mb_lock);
> + mutex_init(&priv->akc_lock);
> +
> + memcpy_fromio(&priv->disc_table, disc_addr, DISC_TABLE_SIZE);
> +
> + ret = sdsi_map_sdsi_registers(pdev);
> + if (ret)
> + goto put_kref;
> +
> + ret = sdsi_create_misc_device(pdev);
> + if (ret)
> + goto put_kref;
> +
> + ret = sdsi_add_bin_attrs(pdev);
You just raced with userspace and lost. Please attach your attributes
to the misc device before registering it.
Also, you need a Documentation/ABI/ entry for your new sysfs file(s).
> + if (ret)
> + goto deregister_misc;
> +
> + priv->dev_present = true;
> +
> + return 0;
> +
> +deregister_misc:
> + misc_deregister(&priv->miscdev);
> +put_kref:
> + kref_put(&priv->kref, sdsi_priv_release);
> +
> + return ret;
> +}
> +
> +static int sdsi_remove(struct platform_device *pdev)
> +{
> + struct sdsi_priv *priv = platform_get_drvdata(pdev);
> +
> + priv->dev_present = false;
> + sysfs_remove_bin_file(&priv->pdev->dev.kobj, &priv->registers_bin_attr);
> + misc_deregister(&priv->miscdev);
> + kref_put(&priv->kref, sdsi_priv_release);
Why do you need a kref for a structure that already can be controlled by
a different lifetime rule?
> +
> + return 0;
> +}
> +
> +static struct platform_driver sdsi_driver = {
> + .driver = {
> + .name = SDSI_DEV_NAME,
> + .dev_groups = sdsi_groups,
> + },
> + .probe = sdsi_probe,
> + .remove = sdsi_remove,
> +};
> +module_platform_driver(sdsi_driver);
What causes the platform to know to register, and enable, this platform
driver? Shouldn't there be some hardware involved that is discoverable
to enable it to load dynamically?
thanks,
greg k-h
