Xen devel - Apr 2012 - [PATCH] xen: use the pirq number to check the pirq_eoi_map

In pirq_check_eoi_map use the pirq number rather than the Linux irq
number to check whether an eoi is needed in the pirq_eoi_map.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Tested-by: Tobias Geiger <tobias.geiger@vido.info>
---
 drivers/xen/events.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 4b33acd..0a8a17c 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -274,7 +274,7 @@ static unsigned int cpu_from_evtchn(unsigned int evtchn)
 
 static bool pirq_check_eoi_map(unsigned irq)
 {
-	return test_bit(irq, pirq_eoi_map);
+	return test_bit(pirq_from_irq(irq), pirq_eoi_map);
 }
 
 static bool pirq_needs_eoi_flag(unsigned irq)
-- 
1.7.2.5

On 25/04/12 16:11, Stefano Stabellini wrote:
> In pirq_check_eoi_map use the pirq number rather than the Linux irq
> number to check whether an eoi is needed in the pirq_eoi_map.
What buggy behaviour does this patch fix?  It would be nice if this was
included in the patch description.

David
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> Tested-by: Tobias Geiger <tobias.geiger@vido.info>
> ---
>  drivers/xen/events.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/xen/events.c b/drivers/xen/events.c
> index 4b33acd..0a8a17c 100644
> --- a/drivers/xen/events.c
> +++ b/drivers/xen/events.c
> @@ -274,7 +274,7 @@ static unsigned int cpu_from_evtchn(unsigned int
evtchn)
>  
>  static bool pirq_check_eoi_map(unsigned irq)
>  {
> -	return test_bit(irq, pirq_eoi_map);
> +	return test_bit(pirq_from_irq(irq), pirq_eoi_map);
>  }
>  
>  static bool pirq_needs_eoi_flag(unsigned irq)

On Thu, 26 Apr 2012, David Vrabel wrote:
> On 25/04/12 16:11, Stefano Stabellini wrote:
> > In pirq_check_eoi_map use the pirq number rather than the Linux irq
> > number to check whether an eoi is needed in the pirq_eoi_map.
> 
> What buggy behaviour does this patch fix?  It would be nice if this was
> included in the patch description.
The irq number is not always identical to the pirq number so if we
wrongly use the irq number to check the pirq_eoi_map we are going to
check for the wrong pirq to EOI. As a consequence some interrupts might
not be EOI''ed by the guest correctly.