Re: [PATCH] hw/acpi: Fix PM control register access

[BALATON Zoltan]

n Sun, 28 May 2023, BALATON Zoltan wrote:
> On pegasos2 which has ACPI as part of VT8231 south bridge the board
> firmware writes PM control register by accessing the second byte so
> addr will be 1. This wasn't handled correctly and the write went to
> addr 0 instead. This fixes ACPI shutdown with pegasos2 firmware.
>
> Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
> ---
> This is replacing the previous attempt which changed enduanness to
> NATIVE_ENDIAN that was found to be wrong. I'm still not sure what's
> happening as these functions are called with addr = 1 and size = 2 but
> maybe the guest really does word access to addr 1 when wanting to
> write 1 byte. This fixes the problem and should not break anything
> else but please review.

Ping?

Regards,
BALATON Zoltan

> hw/acpi/core.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/hw/acpi/core.c b/hw/acpi/core.c
> index 6da275c599..bbc599a252 100644
> --- a/hw/acpi/core.c
> +++ b/hw/acpi/core.c
> @@ -593,13 +593,13 @@ void acpi_pm1_cnt_update(ACPIREGS *ar,
> static uint64_t acpi_pm_cnt_read(void *opaque, hwaddr addr, unsigned width)
> {
>     ACPIREGS *ar = opaque;
> -    return ar->pm1.cnt.cnt;
> +    return ar->pm1.cnt.cnt >> addr * 8;
> }
>
> static void acpi_pm_cnt_write(void *opaque, hwaddr addr, uint64_t val,
>                               unsigned width)
> {
> -    acpi_pm1_cnt_write(opaque, val);
> +    acpi_pm1_cnt_write(opaque, val << addr * 8);
> }
>
> static const MemoryRegionOps acpi_pm_cnt_ops = {