Xen devel - Apr 2013 - [PATCH] xen: clear IRQ_NOAUTOEN and IRQ_NOREQUEST when a VIRQ is bound

Reset the IRQ_NOAUTOEN and IRQ_NOREQUEST flags that are enabled by
default on ARM. If IRQ_NOAUTOEN is set, __setup_irq doesn''t call
irq_startup, that is responsible for calling irq_unmask at startup time.
As a result event channels remain masked.

The clear is already made in bind_evtchn_to_irq with commit a8636c0 but was
missing in bind_virq_to_irq.

Signed-off-by: Julien Grall <julien.grall@linaro.org>
---
 drivers/xen/events.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index d8cc812..b0ad226 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -994,6 +994,7 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
 		WARN_ON(info == NULL || info->type != IRQT_VIRQ);
 	}
 
+	irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN);
 out:
 	mutex_unlock(&irq_mapping_update_lock);
 
-- 
1.7.10.4

On Mon, 29 Apr 2013, Julien Grall wrote:
> Reset the IRQ_NOAUTOEN and IRQ_NOREQUEST flags that are enabled by
> default on ARM. If IRQ_NOAUTOEN is set, __setup_irq doesn''t call
> irq_startup, that is responsible for calling irq_unmask at startup time.
> As a result event channels remain masked.
> 
> The clear is already made in bind_evtchn_to_irq with commit a8636c0 but was
> missing in bind_virq_to_irq.
> 
> Signed-off-by: Julien Grall <julien.grall@linaro.org>
As in the original commit, you should point out that this change does
not have any effects on x86 (where IRQ_NOREQUEST and IRQ_NOAUTOEN are
cleared by default).

At this point we might as well do this consistently everywhere we
allocate a new evtchn irq, including pirqs and ipis, even though we
don''t
actually use them on ARM.

If the call to irq_clear_status_flags can be moved earlier, a good place
for it could be xen_irq_init.

>  drivers/xen/events.c |    1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/xen/events.c b/drivers/xen/events.c
> index d8cc812..b0ad226 100644
> --- a/drivers/xen/events.c
> +++ b/drivers/xen/events.c
> @@ -994,6 +994,7 @@ int bind_virq_to_irq(unsigned int virq, unsigned int
cpu)
>  		WARN_ON(info == NULL || info->type != IRQT_VIRQ);
>  	}
>  
> +	irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN);
>  out:
>  	mutex_unlock(&irq_mapping_update_lock);

On 04/30/2013 04:02 PM, Stefano Stabellini wrote:
> On Mon, 29 Apr 2013, Julien Grall wrote:
>> Reset the IRQ_NOAUTOEN and IRQ_NOREQUEST flags that are enabled by
>> default on ARM. If IRQ_NOAUTOEN is set, __setup_irq doesn''t
call
>> irq_startup, that is responsible for calling irq_unmask at startup
time.
>> As a result event channels remain masked.
>>
>> The clear is already made in bind_evtchn_to_irq with commit a8636c0 but
was
>> missing in bind_virq_to_irq.
>>
>> Signed-off-by: Julien Grall <julien.grall@linaro.org>
> 
> As in the original commit, you should point out that this change does
> not have any effects on x86 (where IRQ_NOREQUEST and IRQ_NOAUTOEN are
> cleared by default).
> 
> At this point we might as well do this consistently everywhere we
> allocate a new evtchn irq, including pirqs and ipis, even though we
don''t
> actually use them on ARM.
> 
> If the call to irq_clear_status_flags can be moved earlier, a good place
> for it could be xen_irq_init.

Thanks for the review. I will give a try and send a version with it if
the solution works.

-- 
Julien