[PATCH v3] crypto: amlogic: Fix IRQ handler return value and fallthrough logic

[Mohamad Raizudeen]

In meson_irq_handler(), when an interrupt matches a flow but the status
register is empty, the driver prints an error but doesn't return. It
falls through the loop and incorrectly prints an `unknown irq` message.

Fix this by returning immediately. For empty status registers, return
IRQ_NONE instead of IRQ_HANDLED to avoid masking spurious interrupts and
allow the kernel to detect interrupt storms. Also use
dev_err_ratelimited() to prevent console lockups during an interrupt
storm.

Additionally, the handler returned IRQ_HANDLED for genuinely unknown
interrupts. Return IRQ_NONE instead for unhandled interrupts.

Cc: stable at vger.kernel.org
Fixes: 48fe583fe5417 ("crypto: amlogic - Add crypto accelerator for amlogic GXL")
Signed-off-by: Mohamad Raizudeen <raizudeen.kerneldev at gmail.com>
---
I have addressed the IRQ specific issues in this v3. The other
pre-exisiting issues mentioned by Sashiko are already addressed in my
separate patch.

Changes in v3:
- Revert accidental clock management changes that were squashed into v2.

Changes in v2:
- Return IRQ_NONE instead of IRQ_HANDLED when status register is empty
  to avoid masking spurious interrupts.
- Use dev_err_ratelimited() to prevent console lockups.

Link to v2: https://lore.kernel.org/all/20260918110504.7207-1-raizudeen.kerneldev@gmail.com/T/

 drivers/crypto/amlogic/amlogic-gxl-core.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/crypto/amlogic/amlogic-gxl-core.c b/drivers/crypto/amlogic/amlogic-gxl-core.c
index 169c6eeb51e5..09d3ccd92b80 100644
--- a/drivers/crypto/amlogic/amlogic-gxl-core.c
+++ b/drivers/crypto/amlogic/amlogic-gxl-core.c
@@ -37,12 +37,13 @@ static irqreturn_t meson_irq_handler(int irq, void *data)
 				complete(&mc->chanlist[flow].complete);
 				return IRQ_HANDLED;
 			}
-			dev_err(mc->dev, "%s %d Got irq for flow %d but ctrl is empty\n", __func__, irq, flow);
+			dev_err_ratelimited(mc->dev, "%s %d Got irq for flow %d but ctrl is empty\n", __func__, irq, flow);
+			return IRQ_NONE;
 		}
 	}
 
-	dev_err(mc->dev, "%s %d from unknown irq\n", __func__, irq);
-	return IRQ_HANDLED;
+	dev_err_ratelimited(mc->dev, "%s %d from unknown irq\n", __func__, irq);
+	return IRQ_NONE;
 }
 
 static struct meson_alg_template mc_algs[] = {
-- 
2.53.0