From: Joel Selvaraj <[email protected]>

In Xiaomi Poco F1 and at least few other devices, the qcom wled driver
triggers unbalanced ovp irq enable warning like the following during
boot up.

[    1.151677] ------------[ cut here ]------------
[    1.151680] Unbalanced enable for IRQ 176
[    1.151693] WARNING: CPU: 0 PID: 160 at kernel/irq/manage.c:774 
__enable_irq+0x50/0x80
[    1.151710] Modules linked in:
[    1.151717] CPU: 0 PID: 160 Comm: kworker/0:11 Not tainted 5.17.0-sdm845 #4
[    1.151724] Hardware name: Xiaomi Pocophone F1 (DT)
[    1.151728] Workqueue: events wled_ovp_work
...<snip>...
[    1.151833] Call trace:
[    1.151836]  __enable_irq+0x50/0x80
[    1.151841]  enable_irq+0x48/0xa0
[    1.151846]  wled_ovp_work+0x18/0x24
[    1.151850]  process_one_work+0x1d0/0x350
[    1.151858]  worker_thread+0x13c/0x460
[    1.151862]  kthread+0x110/0x114
[    1.151868]  ret_from_fork+0x10/0x20
[    1.151876] ---[ end trace 0000000000000000 ]---

Fix it by storing and checking the state of ovp irq before enabling and
disabling it.

Signed-off-by: Joel Selvaraj <[email protected]>
---
I was able to debug the issue a little further. This happens mainly because
devm_request_threaded_irq already enables the ovp irq during probe. Then ovp
work gets scheduled when update_status happens and in turn enables the irq 
again.
Tracking the status makes it easy to avoid the double irq enable. But I am
open to try a different approach if there is any suggestion.
---
Changes in v2:
- Track ovp irq status using ovp_irq_enabled flag instead of ovp_irq_disabled. 
(Konrad Dybcio)
- Use short wrapper functions for ovp irq enable and disable. (Konrad Dybcio)
- Link to v1: 
https://lore.kernel.org/r/20251021-qcom-wled-fix-unbalanced-ovp-irq-enable-v1-1-edd304d16...@joelselvaraj.com
---
 drivers/video/backlight/qcom-wled.c | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/drivers/video/backlight/qcom-wled.c 
b/drivers/video/backlight/qcom-wled.c
index 
a63bb42c8f8b0333cd6d0ddc5bda93916da3fef3..3f49e4b3cdeb12541c057e56bac871a8ff680283
 100644
--- a/drivers/video/backlight/qcom-wled.c
+++ b/drivers/video/backlight/qcom-wled.c
@@ -197,6 +197,7 @@ struct wled {
        bool disabled_by_short;
        bool has_short_detect;
        bool cabc_disabled;
+       bool ovp_irq_enabled;
        int short_irq;
        int ovp_irq;
 
@@ -290,11 +291,27 @@ static int wled5_set_brightness(struct wled *wled, u16 
brightness)
        return rc;
 }
 
+static void wled_enable_ovp_irq(struct wled *wled)
+{
+       if (!wled->ovp_irq_enabled) {
+               enable_irq(wled->ovp_irq);
+               wled->ovp_irq_enabled = true;
+       }
+}
+
+static void wled_disable_ovp_irq(struct wled *wled)
+{
+       if (wled->ovp_irq_enabled) {
+               disable_irq(wled->ovp_irq);
+               wled->ovp_irq_enabled = false;
+       }
+}
+
 static void wled_ovp_work(struct work_struct *work)
 {
        struct wled *wled = container_of(work,
                                         struct wled, ovp_work.work);
-       enable_irq(wled->ovp_irq);
+       wled_enable_ovp_irq(wled);
 }
 
 static int wled_module_enable(struct wled *wled, int val)
@@ -322,7 +339,7 @@ static int wled_module_enable(struct wled *wled, int val)
                        schedule_delayed_work(&wled->ovp_work, HZ / 100);
                } else {
                        if (!cancel_delayed_work_sync(&wled->ovp_work))
-                               disable_irq(wled->ovp_irq);
+                               wled_disable_ovp_irq(wled);
                }
        }
 
@@ -1607,6 +1624,8 @@ static int wled_configure_ovp_irq(struct wled *wled,
                return 0;
        }
 
+       wled->ovp_irq_enabled = true;
+
        rc = regmap_read(wled->regmap, wled->ctrl_addr +
                         WLED3_CTRL_REG_MOD_EN, &val);
        if (rc < 0)
@@ -1614,7 +1633,7 @@ static int wled_configure_ovp_irq(struct wled *wled,
 
        /* Keep OVP irq disabled until module is enabled */
        if (!(val & WLED3_CTRL_REG_MOD_EN_MASK))
-               disable_irq(wled->ovp_irq);
+               wled_disable_ovp_irq(wled);
 
        return 0;
 }
@@ -1726,7 +1745,7 @@ static void wled_remove(struct platform_device *pdev)
        mutex_destroy(&wled->lock);
        cancel_delayed_work_sync(&wled->ovp_work);
        disable_irq(wled->short_irq);
-       disable_irq(wled->ovp_irq);
+       wled_disable_ovp_irq(wled);
 }
 
 static const struct of_device_id wled_match_table[] = {

---
base-commit: fe45352cd106ae41b5ad3f0066c2e54dbb2dfd70
change-id: 20251021-qcom-wled-fix-unbalanced-ovp-irq-enable-5446b106ad96

Best regards,
-- 
Joel Selvaraj <[email protected]>


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