Re: [PATCH v2 5/5] i2c: xlp9xx: fix main IRQ check

Re: [PATCH v2 5/5] i2c: xlp9xx: fix main IRQ check

[George Cherian]

> -----Original Message-----
> From: Wolfram Sang <wsa@kernel.org>
> Sent: Wednesday, August 18, 2021 1:43 AM
> To: Sergey Shtylyov <s.shtylyov@omp.ru>
> Cc: linux-i2c@vger.kernel.org; George Cherian <gcherian@marvell.com>
> Subject: [EXT] Re: [PATCH v2 5/5] i2c: xlp9xx: fix main IRQ check
> 
> On Sun, Jul 04, 2021 at 05:47:54PM +0300, Sergey Shtylyov wrote:
> > Iff platform_get_irq() returns 0 for the main IRQ, the driver's
> > probe() method will return 0 early (as if the method's call was successful).
> > Let's consider IRQ0 valid for simplicity -- devm_request_irq() can
> > always override that decision...
> >
> > Fixes: 2bbd681ba2b ("i2c: xlp9xx: Driver for Netlogic XLP9XX/5XX I2C
> > controller")
> > Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
> >
> 
> George, do you like this patch?
> 
Looks fine. 
Reviewed-by: George Cherian <george.cherian@marvell.com>
> > ---
> >  drivers/i2c/busses/i2c-xlp9xx.c |    2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > Index: linux/drivers/i2c/busses/i2c-xlp9xx.c
> >
> ==========================================================
> =========
> > --- linux.orig/drivers/i2c/busses/i2c-xlp9xx.c
> > +++ linux/drivers/i2c/busses/i2c-xlp9xx.c
> > @@ -517,7 +517,7 @@ static int xlp9xx_i2c_probe(struct platf
> >  		return PTR_ERR(priv->base);
> >
> >  	priv->irq = platform_get_irq(pdev, 0);
> > -	if (priv->irq <= 0)
> > +	if (priv->irq < 0)
> >  		return priv->irq;
> >  	/* SMBAlert irq */
> >  	priv->alert_data.irq = platform_get_irq(pdev, 1);

[PATCH v2 0/5] Correctly handle plaform_get_irq()'s result in the i2C drivers

[Sergey Shtylyov]

Here are 5 patches against the 'i2c/for-current' branch of Wolfram's 'linux.git' repo.
The affected drivers call platform_get_irq() but mis-interprete its result -- they consider
IRQ0 as error and (sometimes) the real error codes as valid IRQs... :-/

[1/5] i2c: hix5hd2: fix IRQ check
[2/5] i2c: mt65xx: fix IRQ check
[3/5] i2c: pmcmsp: fix IRQ check
[4/5] i2c: s3c2410: fix IRQ check
[5/5] i2c: xlp9xx: fix main IRQ check

[PATCH v2 5/5] i2c: xlp9xx: fix main IRQ check

[Sergey Shtylyov]

Iff platform_get_irq() returns 0 for the main IRQ, the driver's probe()
method will return 0 early (as if the method's call was successful).
Let's consider IRQ0 valid for simplicity -- devm_request_irq() can always
override that decision...

Fixes: 2bbd681ba2b ("i2c: xlp9xx: Driver for Netlogic XLP9XX/5XX I2C controller")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>

---
 drivers/i2c/busses/i2c-xlp9xx.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux/drivers/i2c/busses/i2c-xlp9xx.c
===================================================================
--- linux.orig/drivers/i2c/busses/i2c-xlp9xx.c
+++ linux/drivers/i2c/busses/i2c-xlp9xx.c
@@ -517,7 +517,7 @@ static int xlp9xx_i2c_probe(struct platf
 		return PTR_ERR(priv->base);
 
 	priv->irq = platform_get_irq(pdev, 0);
-	if (priv->irq <= 0)
+	if (priv->irq < 0)
 		return priv->irq;
 	/* SMBAlert irq */
 	priv->alert_data.irq = platform_get_irq(pdev, 1);

Re: [PATCH v2 5/5] i2c: xlp9xx: fix main IRQ check

[Wolfram Sang]

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On Sun, Jul 04, 2021 at 05:47:54PM +0300, Sergey Shtylyov wrote:
> Iff platform_get_irq() returns 0 for the main IRQ, the driver's probe()
> method will return 0 early (as if the method's call was successful).
> Let's consider IRQ0 valid for simplicity -- devm_request_irq() can always
> override that decision...
> 
> Fixes: 2bbd681ba2b ("i2c: xlp9xx: Driver for Netlogic XLP9XX/5XX I2C controller")
> Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
> 

George, do you like this patch?

> ---
>  drivers/i2c/busses/i2c-xlp9xx.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Index: linux/drivers/i2c/busses/i2c-xlp9xx.c
> ===================================================================
> --- linux.orig/drivers/i2c/busses/i2c-xlp9xx.c
> +++ linux/drivers/i2c/busses/i2c-xlp9xx.c
> @@ -517,7 +517,7 @@ static int xlp9xx_i2c_probe(struct platf
>  		return PTR_ERR(priv->base);
>  
>  	priv->irq = platform_get_irq(pdev, 0);
> -	if (priv->irq <= 0)
> +	if (priv->irq < 0)
>  		return priv->irq;
>  	/* SMBAlert irq */
>  	priv->alert_data.irq = platform_get_irq(pdev, 1);

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Re: [PATCH v2 5/5] i2c: xlp9xx: fix main IRQ check

[Wolfram Sang]

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On Sun, Jul 04, 2021 at 05:47:54PM +0300, Sergey Shtylyov wrote:
> Iff platform_get_irq() returns 0 for the main IRQ, the driver's probe()
> method will return 0 early (as if the method's call was successful).
> Let's consider IRQ0 valid for simplicity -- devm_request_irq() can always
> override that decision...
> 
> Fixes: 2bbd681ba2b ("i2c: xlp9xx: Driver for Netlogic XLP9XX/5XX I2C controller")
> Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
> 

Applied to for-next, thanks!


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