[PATCH v2] OPP: debugfs: Use performance level if available to distinguish between rates

From: Manivannan Sadhasivam

Date: Fri Jan 30 2026 - 02:20:10 EST


Some OPP tables have entries with same rate and different performance
level. For these entries, using only the rate as the debugfs directory name
causes below error:

debugfs: 'opp:5000000' already exists in 'soc@xxxxxxxxxxxxx'

Fix it by appending the performance level to the dir name if available.

Reported-by: Bjorn Andersson <andersson@xxxxxxxxxx>
Closes: https://lore.kernel.org/linux-arm-msm/75lzykd37zdvrks5i2bb4zb2yzjtm25kv3hegmikndkbr772mz@w2ykff3ny45u/
Fixes: 05db35963eef ("OPP: Add support to find OPP for a set of keys")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxxxxxxxx>
---

Changes in v2:

- Used OPP_LEVEL_UNSET check

drivers/opp/debugfs.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/opp/debugfs.c b/drivers/opp/debugfs.c
index 8fc6238b1728..61506d30d5ff 100644
--- a/drivers/opp/debugfs.c
+++ b/drivers/opp/debugfs.c
@@ -130,22 +130,24 @@ void opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table)
{
struct dentry *pdentry = opp_table->dentry;
struct dentry *d;
- unsigned long id;
- char name[25]; /* 20 chars for 64 bit value + 5 (opp:\0) */
+ char name[36]; /* "opp:"(4) + u64(20) + "-" (1) + u32(10) + NULL(1) */

/*
* Get directory name for OPP.
*
- * - Normally rate is unique to each OPP, use it to get unique opp-name.
+ * - Normally rate is unique to each OPP, use it to get unique opp-name,
+ * together with performance level if available.
* - For some devices rate isn't available or there are multiple, use
* index instead for them.
*/
- if (likely(opp_table->clk_count == 1 && opp->rates[0]))
- id = opp->rates[0];
- else
- id = _get_opp_count(opp_table);
-
- snprintf(name, sizeof(name), "opp:%lu", id);
+ if (likely(opp_table->clk_count == 1 && opp->rates[0])) {
+ if (opp->level == OPP_LEVEL_UNSET)
+ snprintf(name, sizeof(name), "opp:%lu", opp->rates[0]);
+ else
+ snprintf(name, sizeof(name), "opp:%lu-%u", opp->rates[0], opp->level);
+ } else {
+ snprintf(name, sizeof(name), "opp:%u", _get_opp_count(opp_table));
+ }

/* Create per-opp directory */
d = debugfs_create_dir(name, pdentry);
--
2.51.0