[PATCH] clocksource: dw_apb: fix error check

[PATCH] clocksource: dw_apb: fix error check

[Baruch Siach]

irq_of_parse_and_map() returns 0 on error, while the code checks for NO_IRQ.
This breaks on platforms that have NO_IRQ != 0.

Cc: <stable@vger.kernel.org>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
---
 drivers/clocksource/dw_apb_timer_of.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c
index 9fdb4d3..843d43b 100644
--- a/drivers/clocksource/dw_apb_timer_of.c
+++ b/drivers/clocksource/dw_apb_timer_of.c
@@ -47,7 +47,7 @@ static void add_clockevent(struct device_node *event_timer)
 	u32 irq, rate;
 
 	irq = irq_of_parse_and_map(event_timer, 0);
-	if (irq == NO_IRQ)
+	if (irq == 0)
 		panic("No IRQ for clock event timer");
 
 	timer_get_base_and_rate(event_timer, &iobase, &rate);
-- 
1.7.10.4

Re: [PATCH] clocksource: dw_apb: fix error check

[Daniel Lezcano]

On 05/27/2013 01:51 PM, Baruch Siach wrote:
> irq_of_parse_and_map() returns 0 on error, while the code checks for NO_IRQ.
> This breaks on platforms that have NO_IRQ != 0.
> 
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Baruch Siach <baruch@tkos.co.il>
> ---

Shouldn't the 'irq_of_parse_and_map' function to be fixed and return
NO_IRQ in case of error ? (even if some code checks the return value is
'zero' in case of error [1], while some other code checks NO_IRQ [2]).

[1]
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/x86/kernel/devicetree.c#n124

[2]
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/sysdev/fsl_msi.c#n344


>  drivers/clocksource/dw_apb_timer_of.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c
> index 9fdb4d3..843d43b 100644
> --- a/drivers/clocksource/dw_apb_timer_of.c
> +++ b/drivers/clocksource/dw_apb_timer_of.c
> @@ -47,7 +47,7 @@ static void add_clockevent(struct device_node *event_timer)
>  	u32 irq, rate;
>  
>  	irq = irq_of_parse_and_map(event_timer, 0);
> -	if (irq == NO_IRQ)
> +	if (irq == 0)
>  		panic("No IRQ for clock event timer");
>  
>  	timer_get_base_and_rate(event_timer, &iobase, &rate);
> 


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Re: [PATCH] clocksource: dw_apb: fix error check

[Baruch Siach]

Hi Daniel,

On Mon, May 27, 2013 at 03:14:23PM +0200, Daniel Lezcano wrote:
> On 05/27/2013 01:51 PM, Baruch Siach wrote:
> > irq_of_parse_and_map() returns 0 on error, while the code checks for NO_IRQ.
> > This breaks on platforms that have NO_IRQ != 0.
> > 
> > Cc: <stable@vger.kernel.org>
> > Signed-off-by: Baruch Siach <baruch@tkos.co.il>
> > ---
> 
> Shouldn't the 'irq_of_parse_and_map' function to be fixed and return
> NO_IRQ in case of error ? (even if some code checks the return value is
> 'zero' in case of error [1], while some other code checks NO_IRQ [2]).

Probably not. See http://lwn.net/Articles/470820/.

baruch

> [1]
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/x86/kernel/devicetree.c#n124
> 
> [2]
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/sysdev/fsl_msi.c#n344
> 
> 
> >  drivers/clocksource/dw_apb_timer_of.c |    2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c
> > index 9fdb4d3..843d43b 100644
> > --- a/drivers/clocksource/dw_apb_timer_of.c
> > +++ b/drivers/clocksource/dw_apb_timer_of.c
> > @@ -47,7 +47,7 @@ static void add_clockevent(struct device_node *event_timer)
> >  	u32 irq, rate;
> >  
> >  	irq = irq_of_parse_and_map(event_timer, 0);
> > -	if (irq == NO_IRQ)
> > +	if (irq == 0)
> >  		panic("No IRQ for clock event timer");
> >  
> >  	timer_get_base_and_rate(event_timer, &iobase, &rate);

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=}------------------------------------------------ooO--U--Ooo------------{=
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Re: [PATCH] clocksource: dw_apb: fix error check

[Daniel Lezcano]

On 05/27/2013 03:49 PM, Baruch Siach wrote:
> Hi Daniel,
> 
> On Mon, May 27, 2013 at 03:14:23PM +0200, Daniel Lezcano wrote:
>> On 05/27/2013 01:51 PM, Baruch Siach wrote:
>>> irq_of_parse_and_map() returns 0 on error, while the code checks for NO_IRQ.
>>> This breaks on platforms that have NO_IRQ != 0.
>>>
>>> Cc: <stable@vger.kernel.org>
>>> Signed-off-by: Baruch Siach <baruch@tkos.co.il>
>>> ---
>>
>> Shouldn't the 'irq_of_parse_and_map' function to be fixed and return
>> NO_IRQ in case of error ? (even if some code checks the return value is
>> 'zero' in case of error [1], while some other code checks NO_IRQ [2]).
> 
> Probably not. See http://lwn.net/Articles/470820/.

Very interesting. Thx for the pointer !

  -- Daniel

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Re: [PATCH] clocksource: dw_apb: fix error check

[Daniel Lezcano]

On 05/27/2013 01:51 PM, Baruch Siach wrote:
> irq_of_parse_and_map() returns 0 on error, while the code checks for NO_IRQ.
> This breaks on platforms that have NO_IRQ != 0.
> 
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Baruch Siach <baruch@tkos.co.il>
> ---

I queued the patch in my tree [1] for 3.11

Thanks
  -- Daniel

[1]
https://git.linaro.org/gitweb?p=people/dlezcano/clockevents.git;a=shortlog;h=refs/heads/timers/clockevents

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