On Fri, Jun 25, 2021 at 11:30:19PM -0700, longli@xxxxxxxxxxxxxxxxx wrote:
> +#ifdef CONFIG_DEBUG_FS
> +struct dentry *az_blob_debugfs_root;
> +#endif
No need to keep this dentry, just look it up if you need it.
> +
> +static struct az_blob_device az_blob_dev;
> +
> +static int az_blob_ringbuffer_size = (128 * 1024);
> +module_param(az_blob_ringbuffer_size, int, 0444);
> +MODULE_PARM_DESC(az_blob_ringbuffer_size, "Ring buffer size (bytes)");
This is NOT the 1990's, please do not create new module parameters.
Just make this work properly for everyone.
> +#define AZ_ERR 0
> +#define AZ_WARN 1
> +#define AZ_DBG 2
> +static int log_level = AZ_ERR;
> +module_param(log_level, int, 0644);
> +MODULE_PARM_DESC(log_level,
> + "Log level: 0 - Error (default), 1 - Warning, 2 - Debug.");
A single driver does not need a special debug/log level, use the
system-wide functions and all will "just work"
> +
> +static uint device_queue_depth = 1024;
> +module_param(device_queue_depth, uint, 0444);
> +MODULE_PARM_DESC(device_queue_depth,
> + "System level max queue depth for this device");
> +
> +#define az_blob_log(level, fmt, args...) \
> +do { \
> + if (level <= log_level) \
> + pr_err("%s:%d " fmt, __func__, __LINE__, ##args); \
> +} while (0)
> +
> +#define az_blob_dbg(fmt, args...) az_blob_log(AZ_DBG, fmt, ##args)
> +#define az_blob_warn(fmt, args...) az_blob_log(AZ_WARN, fmt, ##args)
> +#define az_blob_err(fmt, args...) az_blob_log(AZ_ERR, fmt, ##args)
Again, no.
Just use dev_dbg(), dev_warn(), and dev_err() and there is no need for
anything "special". This is just one tiny driver, do not rewrite logic
like this for no reason.
> +static void az_blob_remove_device(struct az_blob_device *dev)
> +{
> + wait_event(dev->file_wait, list_empty(&dev->file_list));
> + misc_deregister(&az_blob_misc_device);
> +#ifdef CONFIG_DEBUG_FS
No need for the #ifdef.
> + debugfs_remove_recursive(az_blob_debugfs_root);
> +#endif
> + /* At this point, we won't get any requests from user-mode */
> +}
> +
> +static int az_blob_create_device(struct az_blob_device *dev)
> +{
> + int rc;
> + struct dentry *d;
> +
> + rc = misc_register(&az_blob_misc_device);
> + if (rc) {
> + az_blob_err("misc_register failed rc %d\n", rc);
> + return rc;
> + }
> +
> +#ifdef CONFIG_DEBUG_FS
No need for the #ifdef
> + az_blob_debugfs_root = debugfs_create_dir("az_blob", NULL);
> + if (!IS_ERR_OR_NULL(az_blob_debugfs_root)) {
No need to check this.
> + d = debugfs_create_file("pending_requests", 0400,
> + az_blob_debugfs_root, NULL,
> + &az_blob_debugfs_fops);
> + if (IS_ERR_OR_NULL(d)) {
How can that be NULL?
No need to ever check any debugfs calls, please just make them and move
on.
thanks,
greg k-h
