Using a threaded interrupt without a dedicated primary handler mandates
the IRQF_ONESHOT flag to mask the interrupt source while the threaded
handler is active. Otherwise the interrupt can fire again before the
threaded handler had a chance to run.

Mark explained that this should not happen with this hardware since it
is a slow irqchip which is behind an I2C/ SPI bus but the IRQ-core will
refuse to accept such a handler.

Set IRQF_ONESHOT so the interrupt source is masked until the secondary
handler is done.

Fixes: 1c6c69525b40e ("genirq: Reject bogus threaded irq requests")
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
Cc: Lee Jones <lee@kernel.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: patches@opensource.cirrus.com
Cc: Mark Brown <broonie@kernel.org>
---
 include/linux/mfd/wm8350/core.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/mfd/wm8350/core.h b/include/linux/mfd/wm8350/core.h
index 5f70d3b5d1b1a..097ef4dfcdac8 100644
--- a/include/linux/mfd/wm8350/core.h
+++ b/include/linux/mfd/wm8350/core.h
@@ -667,7 +667,7 @@ static inline int wm8350_register_irq(struct wm8350 *wm8350, int irq,
 		return -ENODEV;
 
 	return request_threaded_irq(irq + wm8350->irq_base, NULL,
-				    handler, flags, name, data);
+				    handler, flags | IRQF_ONESHOT, name, data);
 }
 
 static inline void wm8350_free_irq(struct wm8350 *wm8350, int irq, void *data)
-- 
2.51.0

On Wed, Jan 28, 2026 at 10:55:35AM +0100, Sebastian Andrzej Siewior wrote:
> Using a threaded interrupt without a dedicated primary handler mandates
> the IRQF_ONESHOT flag to mask the interrupt source while the threaded
> handler is active. Otherwise the interrupt can fire again before the
> threaded handler had a chance to run.
> 
> Mark explained that this should not happen with this hardware since it
> is a slow irqchip which is behind an I2C/ SPI bus but the IRQ-core will
> refuse to accept such a handler.
> 
> Set IRQF_ONESHOT so the interrupt source is masked until the secondary
> handler is done.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

-- 
With Best Regards,
Andy Shevchenko

The following commit has been merged into the irq/cleanups branch of tip:

Commit-ID:     553b4999cbe231b5011cb8db05a3092dec168aca
Gitweb:        https://git.kernel.org/tip/553b4999cbe231b5011cb8db05a3092dec168aca
Author:        Sebastian Andrzej Siewior <bigeasy@linutronix.de>
AuthorDate:    Wed, 28 Jan 2026 10:55:35 +01:00
Committer:     Thomas Gleixner <tglx@kernel.org>
CommitterDate: Sun, 01 Feb 2026 17:37:16 +01:00

mfd: wm8350-core: Use IRQF_ONESHOT

Using a threaded interrupt without a dedicated primary handler mandates
the IRQF_ONESHOT flag to mask the interrupt source while the threaded
handler is active. Otherwise the interrupt can fire again before the
threaded handler had a chance to run.

Mark explained that this should not happen with this hardware since it
is a slow irqchip which is behind an I2C/ SPI bus but the IRQ-core will
refuse to accept such a handler.

Set IRQF_ONESHOT so the interrupt source is masked until the secondary
handler is done.

Fixes: 1c6c69525b40e ("genirq: Reject bogus threaded irq requests")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260128095540.863589-16-bigeasy@linutronix.de
---
 include/linux/mfd/wm8350/core.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/mfd/wm8350/core.h b/include/linux/mfd/wm8350/core.h
index 5f70d3b..097ef4d 100644
--- a/include/linux/mfd/wm8350/core.h
+++ b/include/linux/mfd/wm8350/core.h
@@ -667,7 +667,7 @@ static inline int wm8350_register_irq(struct wm8350 *wm8350, int irq,
 		return -ENODEV;
 
 	return request_threaded_irq(irq + wm8350->irq_base, NULL,
-				    handler, flags, name, data);
+				    handler, flags | IRQF_ONESHOT, name, data);
 }
 
 static inline void wm8350_free_irq(struct wm8350 *wm8350, int irq, void *data)