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Date: Mon, 17 Jan 2011 15:37:33 +0100
From: Jan Kiszka <jan.kiszka@siemens.com>
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Subject: [Qemu-devel] Re: [PATCH 8/8] ahci: fix !msi interrupts
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To: Alexander Graf <agraf@suse.de>
Cc: Kevin Wolf <kwolf@redhat.com>, Joerg Roedel <Joerg.Roedel@amd.com>, Sebastian Herbszt <herbszt@gmx.de>, qemu-devel Developers <qemu-devel@nongnu.org>, Gerd Hoffmann <kraxel@redhat.com>

On 2010-12-20 22:13, Alexander Graf wrote:
> When not using MSI, receiving an interrupt while the interrupt line is active
> pulses the interrupt line. Without this, guests don't realize that a new
> interrupt occured.

This doesn't look OK. The device model should look at the currently used
mode and switch between edge and level triggering accordingly. As it
appears like this is what it already does, this change may just paper
over the real issue.

Jan

> 
> Signed-off-by: Alexander Graf <agraf@suse.de>
> ---
>  hw/ide/ahci.c |    3 +--
>  1 files changed, 1 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
> index 97aef68..4c920da 100644
> --- a/hw/ide/ahci.c
> +++ b/hw/ide/ahci.c
> @@ -153,11 +153,10 @@ static void ahci_check_irq(AHCIState *s)
>          }
>      }
>  
> +    ahci_irq_lower(s, NULL);
>      if (s->control_regs.irqstatus &&
>          (s->control_regs.ghc & HOST_CTL_IRQ_EN)) {
>              ahci_irq_raise(s, NULL);
> -    } else {
> -        ahci_irq_lower(s, NULL);
>      }
>  }
>  

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