Re: [Qemu-devel] [PATCH 1.0] malta: Fix regression (i8259 interrupts did not work)

[Peter Maydell <peter.maydell@linaro.org>]

On 24 November 2011 22:07, Stefan Weil <sw@weilnetz.de> wrote:
> Commit 5632ae46d5bda798e971dae48ebb318ac2c3686a passes the address
> of i8259 to qemu_irq_proxy. i8259 was an auto variable with undefined
> value outside of mips_malta_init. This made the proxy unusable.
>
> Ethernet for example no longer worked with MIPS Malta.
>
> There is only one Malta device with one i8259, so using a static
> variable for i8259 is the simplest solution which fixes the problem.
>
> Signed-off-by: Stefan Weil <sw@weilnetz.de>
> ---
>  hw/mips_malta.c |    5 ++++-
>  1 files changed, 4 insertions(+), 1 deletions(-)
>
> diff --git a/hw/mips_malta.c b/hw/mips_malta.c
> index bb49749..e4dc7fb 100644
> --- a/hw/mips_malta.c
> +++ b/hw/mips_malta.c
> @@ -775,7 +775,10 @@ void mips_malta_init (ram_addr_t ram_size,
>     int64_t kernel_entry;
>     PCIBus *pci_bus;
>     CPUState *env;
> -    qemu_irq *i8259 = NULL, *isa_irq;
> +    /* The address of i8259 is passed to qemu_irq_proxy and saved there, but
> +       its value is set later, so it must have a fixed reserved address. */
> +    static qemu_irq *i8259;
> +    qemu_irq *isa_irq;

Yuck. (If boards had state structures the way devices do we'd have
somewhere to put this rather than a local static. More generally
if we have to do this kind of trick then either our device model
is wrong or we're not using it right in this specific situation...)

-- PMM