On Fri, Aug 09, 2013 at 01:37:09PM -0700, Josh Cartwright wrote:

As you never make a pr_* call in this file, this line isn't needed.

__func__ and __LINE__?  Is that really needed, what will it help with?
Seems like extra noise, especially as you only have a few pr_* calls in
this file:

+static int
+spmi_read_data(struct spmi_device *sdev, uint8_t *buf, int offset, int cnt)
+{
+	int ret = 0;
+	int len;
+	uint16_t addr;
+
+	while (cnt > 0) {
+		addr = offset & 0xFFFF;
+		len = min(cnt, MAX_REG_PER_TRANSACTION);
+
+		ret = spmi_ext_register_readl(sdev, addr, buf, len);
+		if (ret < 0) {
+			pr_err("SPMI read failed, err = %d\n", ret);

Should be using dev_err() instead.

+/**
+ * spmi_write_data: writes data across the SPMI bus
+ * @ctrl: The SPMI controller
+ * @buf: data to be written.
+ * @offset: SPMI address offset to start writing to.
+ * @cnt: The number of bytes to write.
+ *
+ * Returns 0 on success, otherwise returns error code from SPMI driver.
+ */
+static int
+spmi_write_data(struct spmi_device *sdev, uint8_t *buf, int offset, int cnt)
+{
+	int ret = 0;
+	int len;
+	uint16_t addr;
+
+	while (cnt > 0) {
+		addr = offset & 0xFFFF;
+		len = min(cnt, MAX_REG_PER_TRANSACTION);
+
+		ret = spmi_ext_register_writel(sdev, addr, buf, len);
+		if (ret < 0) {
+			pr_err("SPMI write failed, err = %d\n", ret);

Same, dev_err() please.

+static ssize_t spmi_device_dfs_reg_write(struct file *file,
+					 const char __user *buf,
+					 size_t count, loff_t *ppos)
+{
+	int bytes_read;
+	int data;
+	int pos = 0;
+	int cnt = 0;
+	u8  *values;
+	size_t ret = 0;
+
+	struct spmi_trans *trans = file->private_data;
+	u32 offset = trans->offset;
+
+	/* Make a copy of the user data */
+	char *kbuf = kmalloc(count + 1, GFP_KERNEL);
+	if (!kbuf)
+		return -ENOMEM;
+
+	ret = copy_from_user(kbuf, buf, count);
+	if (ret == count) {
+		pr_err("failed to copy data from user\n");

No need for a message here at all, you will get a message in the
function if something happened wrong.

Also, shouldn't it just be a simple:
	if (copy_from_user()) {
test?

+		ret = -EFAULT;
+		goto free_buf;
+	}
+
+	count -= ret;
+	*ppos += count;
+	kbuf[count] = '\0';
+
+	/* Override the text buffer with the raw data */
+	values = kbuf;
+
+	/* Parse the data in the buffer.  It should be a string of numbers */
+	while (sscanf(kbuf + pos, "%i%n", &data, &bytes_read) == 1) {
+		pos += bytes_read;
+		values[cnt++] = data & 0xff;
+	}
+
+	if (!cnt)
+		goto free_buf;
+
+	/* Perform the SPMI write(s) */
+	ret = spmi_write_data(trans->sdev, values, offset, cnt);
+
+	if (ret) {
+		pr_err("SPMI write failed, err = %zu\n", ret);

dev_err() please.

+static ssize_t spmi_device_dfs_reg_read(struct file *file, char __user *buf,
+					size_t count, loff_t *ppos)
+{
+	struct spmi_trans *trans = file->private_data;
+	struct spmi_log_buffer *log = trans->log;
+	size_t ret;
+	size_t len;
+
+	/* Is the the log buffer empty */
+	if (log->rpos >= log->wpos) {
+		if (get_log_data(trans) <= 0)
+			return 0;
+	}
+
+	len = min(count, (size_t) log->wpos - log->rpos);
+
+	ret = copy_to_user(buf, &log->data[log->rpos], len);
+	if (ret == len) {
+		pr_err("error copy SPMI register values to user\n");

Same comments as above.

+void __exit spmi_dfs_exit(void)
+{
+	pr_debug("de-initializing spmi debugfs ...");

Not needed, use the in-kernel trace functionality if you really want to
know this.

+	debugfs_remove_recursive(spmi_debug_root);
+}
+
+void __init spmi_dfs_init(void)
+{
+	struct dentry *help;
+
+	pr_debug("creating SPMI debugfs file-system\n");

Same as above, not needed.

So, with those changes, pr_fmt() isn't needed at all :)

Why?  If debugfs isn't enabled, the functions should just compile away
with the debugfs_() calls, so no need to do this type of thing here,
right?

Again, not needed for this file, because:

+int spmi_add_controller(struct spmi_controller *ctrl)
+{
+	int id;
+
+	pr_debug("adding controller for bus %d (0x%p)\n", ctrl->nr, ctrl);

dev_dbg() if you really need/want it.

+
+	if (((int)ctrl->nr) < 0) {
+		pr_err("invalid bus identifier %d\n", ctrl->nr);

dev_err() please.

+		return -EINVAL;
+	}
+
+	idr_preload(GFP_KERNEL);
+	mutex_lock(&board_lock);
+	id = idr_alloc(&ctrl_idr, ctrl, ctrl->nr, ctrl->nr + 1, GFP_NOWAIT);
+	mutex_unlock(&board_lock);
+	idr_preload_end();
+
+	if (id < 0) {
+		pr_err(
+		   "idr_alloc(start:%d end:%d):%d at spmi_add_controller()\n",
+		   ctrl->nr, ctrl->nr, id);

dev_err() please.

And then the pr_fmt() line can be removed.

thanks,

greg k-h