[PATCH] i2c: spacemit: request IRQ after controller initialization

[PATCH] i2c: spacemit: request IRQ after controller initialization

[Linmao Li]

spacemit_i2c_probe() requests the IRQ before it enables the clocks, resets
the controller and runs init_completion(). If an interrupt is already
pending, the handler runs too early: it reads registers while the clocks
are still off and calls complete() on an uninitialized completion. Request
the IRQ after the controller and completion are initialized, but still
before the adapter is registered.

Fixes: 5ea558473fa3 ("i2c: spacemit: add support for SpacemiT K1 SoC")
Signed-off-by: Linmao Li <lilinmao@kylinos.cn>
---
 drivers/i2c/busses/i2c-k1.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/busses/i2c-k1.c b/drivers/i2c/busses/i2c-k1.c
index 51a0c3d80fc9..3fe716cc153d 100644
--- a/drivers/i2c/busses/i2c-k1.c
+++ b/drivers/i2c/busses/i2c-k1.c
@@ -723,11 +723,6 @@ static int spacemit_i2c_probe(struct platform_device *pdev)
 	if (i2c->irq < 0)
 		return dev_err_probe(dev, i2c->irq, "failed to get irq resource");
 
-	ret = devm_request_irq(i2c->dev, i2c->irq, spacemit_i2c_irq_handler,
-			       IRQF_NO_SUSPEND, dev_name(i2c->dev), i2c);
-	if (ret)
-		return dev_err_probe(dev, ret, "failed to request irq");
-
 	clk = devm_clk_get_enabled(dev, "func");
 	if (IS_ERR(clk))
 		return dev_err_probe(dev, PTR_ERR(clk), "failed to enable func clock");
@@ -755,6 +750,11 @@ static int spacemit_i2c_probe(struct platform_device *pdev)
 
 	init_completion(&i2c->complete);
 
+	ret = devm_request_irq(i2c->dev, i2c->irq, spacemit_i2c_irq_handler,
+			       IRQF_NO_SUSPEND, dev_name(i2c->dev), i2c);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to request irq");
+
 	platform_set_drvdata(pdev, i2c);
 
 	ret = i2c_add_numbered_adapter(&i2c->adapt);
-- 
2.25.1


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Re: [PATCH] i2c: spacemit: request IRQ after controller initialization

[Troy Mitchell]

On Wed Jul 22, 2026 at 2:43 AM PDT, Linmao Li wrote:
> spacemit_i2c_probe() requests the IRQ before it enables the clocks, resets
> the controller and runs init_completion(). If an interrupt is already
> pending, the handler runs too early: it reads registers while the clocks
> are still off and calls complete() on an uninitialized completion. Request
> the IRQ after the controller and completion are initialized, but still
> before the adapter is registered.
>
> Fixes: 5ea558473fa3 ("i2c: spacemit: add support for SpacemiT K1 SoC")
> Signed-off-by: Linmao Li <lilinmao@kylinos.cn>
Reviewed-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>

This should also be applied to the stable trees. Please add:
Cc: stable@vger.kernel.org # v6.15+

                            - Troy

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Re: [PATCH] i2c: spacemit: request IRQ after controller initialization

[Alex Elder]

On 7/22/26 4:43 AM, Linmao Li wrote:
> spacemit_i2c_probe() requests the IRQ before it enables the clocks, resets
> the controller and runs init_completion(). If an interrupt is already
> pending, the handler runs too early: it reads registers while the clocks
> are still off and calls complete() on an uninitialized completion. Request
> the IRQ after the controller and completion are initialized, but still
> before the adapter is registered.
> 
> Fixes: 5ea558473fa3 ("i2c: spacemit: add support for SpacemiT K1 SoC")
> Signed-off-by: Linmao Li <lilinmao@kylinos.cn>

This looks correct.

Reviewed-by: Alex Elder <elder@riscstar.com>

> ---
>   drivers/i2c/busses/i2c-k1.c | 10 +++++-----
>   1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-k1.c b/drivers/i2c/busses/i2c-k1.c
> index 51a0c3d80fc9..3fe716cc153d 100644
> --- a/drivers/i2c/busses/i2c-k1.c
> +++ b/drivers/i2c/busses/i2c-k1.c
> @@ -723,11 +723,6 @@ static int spacemit_i2c_probe(struct platform_device *pdev)
>   	if (i2c->irq < 0)
>   		return dev_err_probe(dev, i2c->irq, "failed to get irq resource");
>   
> -	ret = devm_request_irq(i2c->dev, i2c->irq, spacemit_i2c_irq_handler,
> -			       IRQF_NO_SUSPEND, dev_name(i2c->dev), i2c);
> -	if (ret)
> -		return dev_err_probe(dev, ret, "failed to request irq");
> -
>   	clk = devm_clk_get_enabled(dev, "func");
>   	if (IS_ERR(clk))
>   		return dev_err_probe(dev, PTR_ERR(clk), "failed to enable func clock");
> @@ -755,6 +750,11 @@ static int spacemit_i2c_probe(struct platform_device *pdev)
>   
>   	init_completion(&i2c->complete);
>   
> +	ret = devm_request_irq(i2c->dev, i2c->irq, spacemit_i2c_irq_handler,
> +			       IRQF_NO_SUSPEND, dev_name(i2c->dev), i2c);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "failed to request irq");
> +
>   	platform_set_drvdata(pdev, i2c);
>   
>   	ret = i2c_add_numbered_adapter(&i2c->adapt);


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[PATCH v2] i2c: spacemit: request IRQ after controller initialization

[Linmao Li]

spacemit_i2c_probe() requests the IRQ before it enables the clocks, resets
the controller and runs init_completion(). If an interrupt is already
pending, the handler runs too early: it reads registers while the clocks
are still off and calls complete() on an uninitialized completion. Request
the IRQ after the controller and completion are initialized, but still
before the adapter is registered.

Fixes: 5ea558473fa3 ("i2c: spacemit: add support for SpacemiT K1 SoC")
Cc: stable@vger.kernel.org # v6.15+
Signed-off-by: Linmao Li <lilinmao@kylinos.cn>
Reviewed-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
Reviewed-by: Alex Elder <elder@riscstar.com>
---
v2:
- add Cc: stable # v6.15+ as requested by Troy Mitchell
- collect Reviewed-by from Troy Mitchell and Alex Elder

 drivers/i2c/busses/i2c-k1.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/busses/i2c-k1.c b/drivers/i2c/busses/i2c-k1.c
index 51a0c3d80fc9..3fe716cc153d 100644
--- a/drivers/i2c/busses/i2c-k1.c
+++ b/drivers/i2c/busses/i2c-k1.c
@@ -723,11 +723,6 @@ static int spacemit_i2c_probe(struct platform_device *pdev)
 	if (i2c->irq < 0)
 		return dev_err_probe(dev, i2c->irq, "failed to get irq resource");
 
-	ret = devm_request_irq(i2c->dev, i2c->irq, spacemit_i2c_irq_handler,
-			       IRQF_NO_SUSPEND, dev_name(i2c->dev), i2c);
-	if (ret)
-		return dev_err_probe(dev, ret, "failed to request irq");
-
 	clk = devm_clk_get_enabled(dev, "func");
 	if (IS_ERR(clk))
 		return dev_err_probe(dev, PTR_ERR(clk), "failed to enable func clock");
@@ -755,6 +750,11 @@ static int spacemit_i2c_probe(struct platform_device *pdev)
 
 	init_completion(&i2c->complete);
 
+	ret = devm_request_irq(i2c->dev, i2c->irq, spacemit_i2c_irq_handler,
+			       IRQF_NO_SUSPEND, dev_name(i2c->dev), i2c);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to request irq");
+
 	platform_set_drvdata(pdev, i2c);
 
 	ret = i2c_add_numbered_adapter(&i2c->adapt);
-- 
2.25.1


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