[PATCH] irqchip/ti-sci-inta: fix processing of masked irqs

[PATCH] irqchip/ti-sci-inta: fix processing of masked irqs

[Grygorii Strashko]

The ti_sci_inta_irq_handler() does not take into account INTA IRQs state
(masked/unmasked) as it uses INTA_STATUS_CLEAR_j register to get INTA IRQs
status, which provides raw status value.
This causes hard IRQ handlers to be called or threaded handlers to be
scheduled many times even if corresponding INTA IRQ is masked.
Above, first of all, affects the LEVEL interrupts processing and causes
unexpected behavior up the system stack or crash.

Fix it by using the Interrupt Masked Status INTA_STATUSM_j register which
provides masked INTA IRQs status.

Fixes: 9f1463b86c13 ("irqchip/ti-sci-inta: Add support for Interrupt Aggregator driver")
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
 drivers/irqchip/irq-ti-sci-inta.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-ti-sci-inta.c b/drivers/irqchip/irq-ti-sci-inta.c
index 8f6e6b08eadf..7e3ebf6ed2cd 100644
--- a/drivers/irqchip/irq-ti-sci-inta.c
+++ b/drivers/irqchip/irq-ti-sci-inta.c
@@ -37,6 +37,7 @@
 #define VINT_ENABLE_SET_OFFSET	0x0
 #define VINT_ENABLE_CLR_OFFSET	0x8
 #define VINT_STATUS_OFFSET	0x18
+#define VINT_STATUS_MASKED_OFFSET	0x20
 
 /**
  * struct ti_sci_inta_event_desc - Description of an event coming to
@@ -116,7 +117,7 @@ static void ti_sci_inta_irq_handler(struct irq_desc *desc)
 	chained_irq_enter(irq_desc_get_chip(desc), desc);
 
 	val = readq_relaxed(inta->base + vint_desc->vint_id * 0x1000 +
-			    VINT_STATUS_OFFSET);
+			    VINT_STATUS_MASKED_OFFSET);
 
 	for_each_set_bit(bit, &val, MAX_EVENTS_PER_VINT) {
 		virq = irq_find_mapping(domain, vint_desc->events[bit].hwirq);
-- 
2.17.1


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Re: [PATCH] irqchip/ti-sci-inta: fix processing of masked irqs

[Lokesh Vutla]

On 09/04/20 12:45 AM, Grygorii Strashko wrote:
> The ti_sci_inta_irq_handler() does not take into account INTA IRQs state
> (masked/unmasked) as it uses INTA_STATUS_CLEAR_j register to get INTA IRQs
> status, which provides raw status value.
> This causes hard IRQ handlers to be called or threaded handlers to be
> scheduled many times even if corresponding INTA IRQ is masked.
> Above, first of all, affects the LEVEL interrupts processing and causes
> unexpected behavior up the system stack or crash.
> 
> Fix it by using the Interrupt Masked Status INTA_STATUSM_j register which
> provides masked INTA IRQs status.
> 
> Fixes: 9f1463b86c13 ("irqchip/ti-sci-inta: Add support for Interrupt Aggregator driver")
> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>

Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>

Thanks and regards,
Lokesh


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Re: [PATCH] irqchip/ti-sci-inta: fix processing of masked irqs

[Marc Zyngier]

On Wed, 8 Apr 2020 22:15:32 +0300
Grygorii Strashko <grygorii.strashko@ti.com> wrote:

> The ti_sci_inta_irq_handler() does not take into account INTA IRQs state
> (masked/unmasked) as it uses INTA_STATUS_CLEAR_j register to get INTA IRQs
> status, which provides raw status value.
> This causes hard IRQ handlers to be called or threaded handlers to be
> scheduled many times even if corresponding INTA IRQ is masked.
> Above, first of all, affects the LEVEL interrupts processing and causes
> unexpected behavior up the system stack or crash.
> 
> Fix it by using the Interrupt Masked Status INTA_STATUSM_j register which
> provides masked INTA IRQs status.
> 
> Fixes: 9f1463b86c13 ("irqchip/ti-sci-inta: Add support for Interrupt Aggregator driver")
> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>

Given the failure mode, doesn't this deserve a Cc stable?

> ---
>  drivers/irqchip/irq-ti-sci-inta.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/irqchip/irq-ti-sci-inta.c b/drivers/irqchip/irq-ti-sci-inta.c
> index 8f6e6b08eadf..7e3ebf6ed2cd 100644
> --- a/drivers/irqchip/irq-ti-sci-inta.c
> +++ b/drivers/irqchip/irq-ti-sci-inta.c
> @@ -37,6 +37,7 @@
>  #define VINT_ENABLE_SET_OFFSET	0x0
>  #define VINT_ENABLE_CLR_OFFSET	0x8
>  #define VINT_STATUS_OFFSET	0x18
> +#define VINT_STATUS_MASKED_OFFSET	0x20
>  
>  /**
>   * struct ti_sci_inta_event_desc - Description of an event coming to
> @@ -116,7 +117,7 @@ static void ti_sci_inta_irq_handler(struct irq_desc *desc)
>  	chained_irq_enter(irq_desc_get_chip(desc), desc);
>  
>  	val = readq_relaxed(inta->base + vint_desc->vint_id * 0x1000 +
> -			    VINT_STATUS_OFFSET);
> +			    VINT_STATUS_MASKED_OFFSET);
>  
>  	for_each_set_bit(bit, &val, MAX_EVENTS_PER_VINT) {
>  		virq = irq_find_mapping(domain, vint_desc->events[bit].hwirq);


Otherwise queued for post -rc1.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

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Re: [PATCH] irqchip/ti-sci-inta: fix processing of masked irqs

[Grygorii Strashko]

On 09/04/2020 12:31, Marc Zyngier wrote:
> On Wed, 8 Apr 2020 22:15:32 +0300
> Grygorii Strashko <grygorii.strashko@ti.com> wrote:
> 
>> The ti_sci_inta_irq_handler() does not take into account INTA IRQs state
>> (masked/unmasked) as it uses INTA_STATUS_CLEAR_j register to get INTA IRQs
>> status, which provides raw status value.
>> This causes hard IRQ handlers to be called or threaded handlers to be
>> scheduled many times even if corresponding INTA IRQ is masked.
>> Above, first of all, affects the LEVEL interrupts processing and causes
>> unexpected behavior up the system stack or crash.
>>
>> Fix it by using the Interrupt Masked Status INTA_STATUSM_j register which
>> provides masked INTA IRQs status.
>>
>> Fixes: 9f1463b86c13 ("irqchip/ti-sci-inta: Add support for Interrupt Aggregator driver")
>> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
> 
> Given the failure mode, doesn't this deserve a Cc stable?

Sorry, was not sure how it works here.
"Fixes" tag now is usually enough to get included in stable.
Any way, I'll track it and if not included will re-send for stable.

> 
>> ---
>>   drivers/irqchip/irq-ti-sci-inta.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/irqchip/irq-ti-sci-inta.c b/drivers/irqchip/irq-ti-sci-inta.c
>> index 8f6e6b08eadf..7e3ebf6ed2cd 100644
>> --- a/drivers/irqchip/irq-ti-sci-inta.c
>> +++ b/drivers/irqchip/irq-ti-sci-inta.c
>> @@ -37,6 +37,7 @@
>>   #define VINT_ENABLE_SET_OFFSET	0x0
>>   #define VINT_ENABLE_CLR_OFFSET	0x8
>>   #define VINT_STATUS_OFFSET	0x18
>> +#define VINT_STATUS_MASKED_OFFSET	0x20
>>   
>>   /**
>>    * struct ti_sci_inta_event_desc - Description of an event coming to
>> @@ -116,7 +117,7 @@ static void ti_sci_inta_irq_handler(struct irq_desc *desc)
>>   	chained_irq_enter(irq_desc_get_chip(desc), desc);
>>   
>>   	val = readq_relaxed(inta->base + vint_desc->vint_id * 0x1000 +
>> -			    VINT_STATUS_OFFSET);
>> +			    VINT_STATUS_MASKED_OFFSET);
>>   
>>   	for_each_set_bit(bit, &val, MAX_EVENTS_PER_VINT) {
>>   		virq = irq_find_mapping(domain, vint_desc->events[bit].hwirq);
> 
> 
> Otherwise queued for post -rc1.

Thanks.

-- 
Best regards,
grygorii

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Re: [PATCH] irqchip/ti-sci-inta: fix processing of masked irqs

[Marc Zyngier]

On Thu, 9 Apr 2020 14:11:12 +0300
Grygorii Strashko <grygorii.strashko@ti.com> wrote:

> On 09/04/2020 12:31, Marc Zyngier wrote:
> > On Wed, 8 Apr 2020 22:15:32 +0300
> > Grygorii Strashko <grygorii.strashko@ti.com> wrote:
> >   
> >> The ti_sci_inta_irq_handler() does not take into account INTA IRQs state
> >> (masked/unmasked) as it uses INTA_STATUS_CLEAR_j register to get INTA IRQs
> >> status, which provides raw status value.
> >> This causes hard IRQ handlers to be called or threaded handlers to be
> >> scheduled many times even if corresponding INTA IRQ is masked.
> >> Above, first of all, affects the LEVEL interrupts processing and causes
> >> unexpected behavior up the system stack or crash.
> >>
> >> Fix it by using the Interrupt Masked Status INTA_STATUSM_j register which
> >> provides masked INTA IRQs status.
> >>
> >> Fixes: 9f1463b86c13 ("irqchip/ti-sci-inta: Add support for Interrupt Aggregator driver")
> >> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>  
> > 
> > Given the failure mode, doesn't this deserve a Cc stable?  
> 
> Sorry, was not sure how it works here.
> "Fixes" tag now is usually enough to get included in stable.
> Any way, I'll track it and if not included will re-send for stable.

Last time I asked, Greg was adamant that a Cc: stable was needed to
guarantee a backport. In some cases, the patch is picked up anyway, but
it doesn't hurt to have the stable tag if you think it should be
backported.

Anyway, I've now added such tag.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

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