Re: [PATCH v13 2/3] i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver

From: Andy Shevchenko
Date: Fri May 22 2020 - 08:27:37 EST


On Fri, May 22, 2020 at 02:33:11PM +0300, Tali Perry wrote:
> Add Nuvoton NPCM BMC I2C controller driver.

I thought we are waiting for Wolfram finishing his review...


In any case see couple of comments below.

...


> +#ifdef CONFIG_DEBUG_FS

Now, do we need the rest of DEBUG_FS guards?

> + if (status) {
> + if (bus->rec_fail_cnt == ULLONG_MAX) {
> + dev_dbg(bus->dev, "rec_fail_cnt reach max, reset to 0");

> + bus->rec_fail_cnt = 0;

It's redundant, since we will anyway roll over when incrementing.
https://stackoverflow.com/q/18195715/2511795

> + }
> + bus->rec_fail_cnt++;
> + } else {
> + if (bus->rec_succ_cnt == ULLONG_MAX) {
> + dev_dbg(bus->dev, "rec_succ_cnt reach max, reset to 0");

> + bus->rec_succ_cnt = 0;

Ditto.

> + }
> + bus->rec_succ_cnt++;
> + }
> +#endif

...

> +static int npcm_i2c_remove_bus(struct platform_device *pdev)
> +{
> + unsigned long lock_flags;
> + struct npcm_i2c *bus = platform_get_drvdata(pdev);
> +
> + spin_lock_irqsave(&bus->lock, lock_flags);
> + npcm_i2c_disable(bus);
> + spin_unlock_irqrestore(&bus->lock, lock_flags);
> + i2c_del_adapter(&bus->adap);

> + debugfs_remove_recursive(bus->debugfs);

This should be in reversed order, i.e. you inited last in ->probe(), thus
should remove first in ->remove().

> + return 0;
> +}

...

> +static int __init npcm_i2c_init(void)
> +{
> + struct dentry *dir;
> +
> + dir = debugfs_create_dir("i2c", NULL);

> + if (IS_ERR_OR_NULL(dir))

IS_ERR() is redundant. And NULL already being checked inside i2c_init_debugfs()
or how do you call it?

> + return 0;
> +
> + npcm_i2c_debugfs_dir = dir;
> + return 0;
> +}
> +
> +static void __exit npcm_i2c_exit(void)
> +{
> + debugfs_remove_recursive(npcm_i2c_debugfs_dir);
> +}

> +
> +module_init(npcm_i2c_init);
> +module_exit(npcm_i2c_exit);

Slightly better to attach to the respective function, like other macros above
do.

--
With Best Regards,
Andy Shevchenko