[PATCH v4] mfd: intel-lpss: Prevent DebugFS messages if it is not initialized

[Maria Lisina via B4 Relay <devnull+sekoohaka.sarisan.gmail.com@kernel.org>]

From: Maria Lisina <sekoohaka.sarisan@gmail.com>

The original code expects DebugFS to be always initialized which
causes unwanted warnings when DebugFS is simply disabled.

Therefore it spams dmesg with these messages:

  intel-lpss 0000:00:15.0: Failed to create debugfs entries
  intel-lpss 0000:00:15.3: Failed to create debugfs entries
  intel-lpss 0000:00:1e.0: Failed to create debugfs entries
  intel-lpss 0000:00:1e.2: Failed to create debugfs entries

This patch adds proper check to intel_lpss_init() and
intel_lpss_debugfs_add() functions to prevent writing to
uninitialized DebugFS.

Signed-off-by: Maria Lisina <sekoohaka.sarisan@gmail.com>
---
Changes in v4:
- Keep the dmesg messages, instead check whether DebugFS is initialized
- Link to v3: https://lore.kernel.org/r/20260913-intel-lpss-debugfs-v3-1-1b8e2b1f0992@gmail.com

Changes in v3:
- Fixed commit name and description.
- Link to v2: https://lore.kernel.org/r/20260913-intel-lpss-debugfs-v2-1-a1a4faf5cc63@gmail.com

Changes in v2:
- Fixed function name in comment section.
- Link to v1: https://lore.kernel.org/r/20260913-intel-lpss-debugfs-v1-1-833cbb6fffc9@gmail.com
---
 drivers/mfd/intel-lpss.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c
index 63d6694f71457b2e09d238af0a9bfb897a169a64..d45728f46c499b3f0c3713d30a17b0ae12106095 100644
--- a/drivers/mfd/intel-lpss.c
+++ b/drivers/mfd/intel-lpss.c
@@ -146,6 +146,12 @@ static int intel_lpss_debugfs_add(struct intel_lpss *lpss)
 {
 	struct dentry *dir;
 
+	/* Exit if DebugFS is not initialized */
+	if (!intel_lpss_debugfs) {
+		lpss->debugfs = NULL;
+		return 0;
+	}
+
 	dir = debugfs_create_dir(dev_name(lpss->dev), intel_lpss_debugfs);
 	if (IS_ERR(dir))
 		return PTR_ERR(dir);
@@ -538,7 +544,15 @@ EXPORT_NS_GPL_DEV_PM_OPS(intel_lpss_pm_ops, INTEL_LPSS) = {
 
 static int __init intel_lpss_init(void)
 {
-	intel_lpss_debugfs = debugfs_create_dir("intel_lpss", NULL);
+	/*
+	 * Check whether DebugFS is initialized to
+	 * prevent unwanted dmesg messages.
+	 */
+	if (debugfs_initialized())
+		intel_lpss_debugfs = debugfs_create_dir("intel_lpss", NULL);
+	else
+		intel_lpss_debugfs = NULL;
+
 	return 0;
 }
 module_init(intel_lpss_init);

---
base-commit: 2f0c1cf72f4682178506f513bbf015e591b1aa4a
change-id: 20260913-intel-lpss-debugfs-eff3580d1295

Best regards,
-- 
Maria Lisina <sekoohaka.sarisan@gmail.com>