[PATCH] spi: limit reaches -1, tested 0

[PATCH] spi: limit reaches -1, tested 0

[Roel Kluin]

With a postfix decrement limit will reach -1 rather than 0,
so the warning will not be issued.

Signed-off-by: Roel Kluin <roel.kluin-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c
index 269a55e..a4652f1 100644
--- a/drivers/spi/spi_imx.c
+++ b/drivers/spi/spi_imx.c
@@ -779,7 +779,7 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
 
 			/* Read trailing bytes */
 			limit = loops_per_jiffy << 1;
-			while ((read(drv_data) == 0) && limit--);
+			while ((read(drv_data) == 0) && --limit);
 
 			if (limit == 0)
 				dev_err(&drv_data->pdev->dev,

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[PATCH] spi: limit reaches -1, tested 0

[Roel Kluin]

With a postfix decrement limit will reach -1 rather than 0,
so the warning will not be issued.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
---
diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c
index 269a55e..a4652f1 100644
--- a/drivers/spi/spi_imx.c
+++ b/drivers/spi/spi_imx.c
@@ -779,7 +779,7 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
 
 			/* Read trailing bytes */
 			limit = loops_per_jiffy << 1;
-			while ((read(drv_data) == 0) && limit--);
+			while ((read(drv_data) == 0) && --limit);
 
 			if (limit == 0)
 				dev_err(&drv_data->pdev->dev,

Re: [PATCH] spi: limit reaches -1, tested 0

[David Brownell]

On Sunday 08 February 2009, Roel Kluin wrote:
> With a postfix decrement limit will reach -1 rather than 0,
> so the warning will not be issued.
> 
> Signed-off-by: Roel Kluin <roel.kluin-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

Acked-by: David Brownell <dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>



> ---
> diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c
> index 269a55e..a4652f1 100644
> --- a/drivers/spi/spi_imx.c
> +++ b/drivers/spi/spi_imx.c
> @@ -779,7 +779,7 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
>  
>  			/* Read trailing bytes */
>  			limit = loops_per_jiffy << 1;
> -			while ((read(drv_data) == 0) && limit--);
> +			while ((read(drv_data) == 0) && --limit);
>  
>  			if (limit == 0)
>  				dev_err(&drv_data->pdev->dev,
> 
> 



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Re: [PATCH] spi: limit reaches -1, tested 0

[David Brownell]

On Sunday 08 February 2009, Roel Kluin wrote:
> With a postfix decrement limit will reach -1 rather than 0,
> so the warning will not be issued.
> 
> Signed-off-by: Roel Kluin <roel.kluin@gmail.com>

Acked-by: David Brownell <dbrownell@users.sourceforge.net>



> ---
> diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c
> index 269a55e..a4652f1 100644
> --- a/drivers/spi/spi_imx.c
> +++ b/drivers/spi/spi_imx.c
> @@ -779,7 +779,7 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
>  
>  			/* Read trailing bytes */
>  			limit = loops_per_jiffy << 1;
> -			while ((read(drv_data) == 0) && limit--);
> +			while ((read(drv_data) == 0) && --limit);
>  
>  			if (limit == 0)
>  				dev_err(&drv_data->pdev->dev,
> 
> 

Re: [PATCH] spi: limit reaches -1, tested 0

[David Brownell]

On Sunday 08 February 2009, David Brownell wrote:
> On Sunday 08 February 2009, Roel Kluin wrote:
> > With a postfix decrement limit will reach -1 rather than 0,
> > so the warning will not be issued.
> > 
> > Signed-off-by: Roel Kluin <roel.kluin-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> 
> Acked-by: David Brownell <dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
> 
> 
> 
> > ---
> > diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c
> > index 269a55e..a4652f1 100644
> > --- a/drivers/spi/spi_imx.c
> > +++ b/drivers/spi/spi_imx.c
> > @@ -779,7 +779,7 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
> >  
> >  			/* Read trailing bytes */
> >  			limit = loops_per_jiffy << 1;
> > -			while ((read(drv_data) == 0) && limit--);
> > +			while ((read(drv_data) == 0) && --limit);

... although I wouldn't have resisted the urge to make the
loop body be "cpu_relax();" instead of an empty statement.


> >  
> >  			if (limit == 0)
> >  				dev_err(&drv_data->pdev->dev,
> > 
> > 
> 
> 
> 



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Re: [PATCH] spi: limit reaches -1, tested 0

[David Brownell]

On Sunday 08 February 2009, David Brownell wrote:
> On Sunday 08 February 2009, Roel Kluin wrote:
> > With a postfix decrement limit will reach -1 rather than 0,
> > so the warning will not be issued.
> > 
> > Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
> 
> Acked-by: David Brownell <dbrownell@users.sourceforge.net>
> 
> 
> 
> > ---
> > diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c
> > index 269a55e..a4652f1 100644
> > --- a/drivers/spi/spi_imx.c
> > +++ b/drivers/spi/spi_imx.c
> > @@ -779,7 +779,7 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
> >  
> >  			/* Read trailing bytes */
> >  			limit = loops_per_jiffy << 1;
> > -			while ((read(drv_data) == 0) && limit--);
> > +			while ((read(drv_data) == 0) && --limit);

... although I wouldn't have resisted the urge to make the
loop body be "cpu_relax();" instead of an empty statement.


> >  
> >  			if (limit == 0)
> >  				dev_err(&drv_data->pdev->dev,
> > 
> > 
> 
> 
> 

Re: [PATCH] spi: limit reaches -1, tested 0

[Roel Kluin]

>>> -			while ((read(drv_data) == 0) && limit--);
>>> +			while ((read(drv_data) == 0) && --limit);
> 
> ... although I wouldn't have resisted the urge to make the
> loop body be "cpu_relax();" instead of an empty statement.

Ok,
---------------------------->8-------------------8<-----------------------------
With a postfix decrement limit will reach -1 rather than 0, so the warning will
not be issued.

Signed-off-by: Roel Kluin <roel.kluin-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c
index 269a55e..15abe61 100644
--- a/drivers/spi/spi_imx.c
+++ b/drivers/spi/spi_imx.c
@@ -779,7 +779,8 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
 
 			/* Read trailing bytes */
 			limit = loops_per_jiffy << 1;
-			while ((read(drv_data) == 0) && limit--);
+			while ((read(drv_data) == 0) && limit--)
+				cpu_relax();
 
 			if (limit == 0)
 				dev_err(&drv_data->pdev->dev,

------------------------------------------------------------------------------
Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM)
software. With Adobe AIR, Ajax developers can use existing skills and code to
build responsive, highly engaging applications that combine the power of local
resources and data with the reach of the web. Download the Adobe AIR SDK and
Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com

Re: [PATCH] spi: limit reaches -1, tested 0

[Roel Kluin]

>>> -			while ((read(drv_data) == 0) && limit--);
>>> +			while ((read(drv_data) == 0) && --limit);
> 
> ... although I wouldn't have resisted the urge to make the
> loop body be "cpu_relax();" instead of an empty statement.

Ok,
---------------------------->8-------------------8<-----------------------------
With a postfix decrement limit will reach -1 rather than 0, so the warning will
not be issued.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
---
diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c
index 269a55e..15abe61 100644
--- a/drivers/spi/spi_imx.c
+++ b/drivers/spi/spi_imx.c
@@ -779,7 +779,8 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
 
 			/* Read trailing bytes */
 			limit = loops_per_jiffy << 1;
-			while ((read(drv_data) == 0) && limit--);
+			while ((read(drv_data) == 0) && limit--)
+				cpu_relax();
 
 			if (limit == 0)
 				dev_err(&drv_data->pdev->dev,

Re: [PATCH] spi: limit reaches -1, tested 0

[David Brownell]

On Sunday 08 February 2009, Roel Kluin wrote:
> >>> -			while ((read(drv_data) == 0) && limit--);
> >>> +			while ((read(drv_data) == 0) && --limit);
> > 
> > ... although I wouldn't have resisted the urge to make the
> > loop body be "cpu_relax();" instead of an empty statement.
> 
> Ok,
> ---------------------------->8-------------------8<-----------------------------
> With a postfix decrement limit will reach -1 rather than 0, so the warning will
> not be issued.
> 
> Signed-off-by: Roel Kluin <roel.kluin-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

Still:

Acked-by: David Brownell <dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>


> ---
> diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c
> index 269a55e..15abe61 100644
> --- a/drivers/spi/spi_imx.c
> +++ b/drivers/spi/spi_imx.c
> @@ -779,7 +779,8 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
>  
>  			/* Read trailing bytes */
>  			limit = loops_per_jiffy << 1;
> -			while ((read(drv_data) == 0) && limit--);
> +			while ((read(drv_data) == 0) && limit--)
> +				cpu_relax();
>  
>  			if (limit == 0)
>  				dev_err(&drv_data->pdev->dev,
> 
> 



------------------------------------------------------------------------------
Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM)
software. With Adobe AIR, Ajax developers can use existing skills and code to
build responsive, highly engaging applications that combine the power of local
resources and data with the reach of the web. Download the Adobe AIR SDK and
Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com

Re: [PATCH] spi: limit reaches -1, tested 0

[David Brownell]

On Sunday 08 February 2009, Roel Kluin wrote:
> >>> -			while ((read(drv_data) == 0) && limit--);
> >>> +			while ((read(drv_data) == 0) && --limit);
> > 
> > ... although I wouldn't have resisted the urge to make the
> > loop body be "cpu_relax();" instead of an empty statement.
> 
> Ok,
> ---------------------------->8-------------------8<-----------------------------
> With a postfix decrement limit will reach -1 rather than 0, so the warning will
> not be issued.
> 
> Signed-off-by: Roel Kluin <roel.kluin@gmail.com>

Still:

Acked-by: David Brownell <dbrownell@users.sourceforge.net>


> ---
> diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c
> index 269a55e..15abe61 100644
> --- a/drivers/spi/spi_imx.c
> +++ b/drivers/spi/spi_imx.c
> @@ -779,7 +779,8 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
>  
>  			/* Read trailing bytes */
>  			limit = loops_per_jiffy << 1;
> -			while ((read(drv_data) == 0) && limit--);
> +			while ((read(drv_data) == 0) && limit--)
> +				cpu_relax();
>  
>  			if (limit == 0)
>  				dev_err(&drv_data->pdev->dev,
> 
> 

Re: [PATCH] spi: limit reaches -1, tested 0

[Mariusz Ceier]

Roel Kluin writes in first post:
> -			while ((read(drv_data) == 0) && limit--);
> +			while ((read(drv_data) == 0) && --limit);

Roel Kluin writes in last post:
> -			while ((read(drv_data) == 0) && limit--);
> +			while ((read(drv_data) == 0) && limit--)
> +				cpu_relax();

so should there be postfix or prefix decrement ? :)

Mariusz Ceier



------------------------------------------------------------------------------
Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM)
software. With Adobe AIR, Ajax developers can use existing skills and code to
build responsive, highly engaging applications that combine the power of local
resources and data with the reach of the web. Download the Adobe AIR SDK and
Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com

Re: [PATCH] spi: limit reaches -1, tested 0

[Mariusz Ceier]

Roel Kluin writes in first post:
> -			while ((read(drv_data) == 0) && limit--);
> +			while ((read(drv_data) == 0) && --limit);

Roel Kluin writes in last post:
> -			while ((read(drv_data) == 0) && limit--);
> +			while ((read(drv_data) == 0) && limit--)
> +				cpu_relax();

so should there be postfix or prefix decrement ? :)

Mariusz Ceier

Re: [PATCH] spi: limit reaches -1, tested 0

[Roel Kluin]

Mariusz Ceier wrote:
> Roel Kluin writes in first post:
>> -			while ((read(drv_data) == 0) && limit--);
>> +			while ((read(drv_data) == 0) && --limit);
> 
> Roel Kluin writes in last post:
>> -			while ((read(drv_data) == 0) && limit--);
>> +			while ((read(drv_data) == 0) && limit--)
>> +				cpu_relax();
> 
> so should there be postfix or prefix decrement ? :)

Thanks for spotting, I took the liberty to add David Brownell's Acked-by
in this case.
----------------------->8------------------8<---------------------------
With a postfix decrement limit will reach -1 rather than 0,
so the warning will not be issued.

Signed-off-by: Roel Kluin <roel.kluin-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Acked-by: David Brownell <dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
---
diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c
index 269a55e..b143e8c 100644
--- a/drivers/spi/spi_imx.c
+++ b/drivers/spi/spi_imx.c
@@ -779,7 +779,8 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
 
 			/* Read trailing bytes */
 			limit = loops_per_jiffy << 1;
-			while ((read(drv_data) == 0) && limit--);
+			while ((read(drv_data) == 0) && --limit)
+				cpu_relax();
 
 			if (limit == 0)
 				dev_err(&drv_data->pdev->dev,

------------------------------------------------------------------------------
Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM)
software. With Adobe AIR, Ajax developers can use existing skills and code to
build responsive, highly engaging applications that combine the power of local
resources and data with the reach of the web. Download the Adobe AIR SDK and
Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com

Re: [PATCH] spi: limit reaches -1, tested 0

[Roel Kluin]

Mariusz Ceier wrote:
> Roel Kluin writes in first post:
>> -			while ((read(drv_data) == 0) && limit--);
>> +			while ((read(drv_data) == 0) && --limit);
> 
> Roel Kluin writes in last post:
>> -			while ((read(drv_data) == 0) && limit--);
>> +			while ((read(drv_data) == 0) && limit--)
>> +				cpu_relax();
> 
> so should there be postfix or prefix decrement ? :)

Thanks for spotting, I took the liberty to add David Brownell's Acked-by
in this case.
----------------------->8------------------8<---------------------------
With a postfix decrement limit will reach -1 rather than 0,
so the warning will not be issued.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
---
diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c
index 269a55e..b143e8c 100644
--- a/drivers/spi/spi_imx.c
+++ b/drivers/spi/spi_imx.c
@@ -779,7 +779,8 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
 
 			/* Read trailing bytes */
 			limit = loops_per_jiffy << 1;
-			while ((read(drv_data) == 0) && limit--);
+			while ((read(drv_data) == 0) && --limit)
+				cpu_relax();
 
 			if (limit == 0)
 				dev_err(&drv_data->pdev->dev,