[Qemu-devel] Re: sparc32 fix spurious dma interrupts v2

[Blue Swirl <blauwirbel@gmail.com>]

Thanks, applied.


On Mon, Feb 15, 2010 at 7:39 PM, Artyom Tarasenko
<atar4qemu@googlemail.com> wrote:
> Don't raise irq when not enabled.
> Raise irq on enabling if DMA_INTR is set
> Don't clear irq unless it was raised by DMA, as there are other irq sources
> Don't set DMA_INTR bit spuriously.
>
> v1->v2:
>  - Don't clear irq unless it was raised by DMA
>  - Raise irq on enabling if DMA_INTR is set
>  - Assume revertion of 787cfbc432bf1d353a77cbdb613754f3963371a3
>
> Signed-off-by: Artyom Tarasenko <atar4qemu@gmail.com>
> ---
> diff --git a/hw/sparc32_dma.c b/hw/sparc32_dma.c
> index faf6dbc..18ba035 100644
> --- a/hw/sparc32_dma.c
> +++ b/hw/sparc32_dma.c
> @@ -3,6 +3,9 @@
>  *
>  * Copyright (c) 2006 Fabrice Bellard
>  *
> + * Modifications:
> + *  2010-Feb-14 Artyom Tarasenko : reworked irq generation
> + *
>  * Permission is hereby granted, free of charge, to any person obtaining a copy
>  * of this software and associated documentation files (the "Software"), to deal
>  * in the Software without restriction, including without limitation the rights
> @@ -125,13 +128,19 @@ static void dma_set_irq(void *opaque, int irq, int level)
>  {
>     DMAState *s = opaque;
>     if (level) {
> -        DPRINTF("Raise IRQ\n");
>         s->dmaregs[0] |= DMA_INTR;
> -        qemu_irq_raise(s->irq);
> +        if (s->dmaregs[0] & DMA_INTREN) {
> +            DPRINTF("Raise IRQ\n");
> +            qemu_irq_raise(s->irq);
> +        }
>     } else {
> -        s->dmaregs[0] &= ~DMA_INTR;
> -        DPRINTF("Lower IRQ\n");
> -        qemu_irq_lower(s->irq);
> +        if (s->dmaregs[0] & DMA_INTR) {
> +            s->dmaregs[0] &= ~DMA_INTR;
> +            if (s->dmaregs[0] & DMA_INTREN) {
> +                DPRINTF("Lower IRQ\n");
> +                qemu_irq_lower(s->irq);
> +            }
> +        }
>     }
>  }
>
> @@ -142,7 +151,6 @@ void espdma_memory_read(void *opaque, uint8_t *buf, int len)
>     DPRINTF("DMA read, direction: %c, addr 0x%8.8x\n",
>             s->dmaregs[0] & DMA_WRITE_MEM ? 'w': 'r', s->dmaregs[1]);
>     sparc_iommu_memory_read(s->iommu, s->dmaregs[1], buf, len);
> -    s->dmaregs[0] |= DMA_INTR;
>     s->dmaregs[1] += len;
>  }
>
> @@ -153,7 +161,6 @@ void espdma_memory_write(void *opaque, uint8_t *buf, int len)
>     DPRINTF("DMA write, direction: %c, addr 0x%8.8x\n",
>             s->dmaregs[0] & DMA_WRITE_MEM ? 'w': 'r', s->dmaregs[1]);
>     sparc_iommu_memory_write(s->iommu, s->dmaregs[1], buf, len);
> -    s->dmaregs[0] |= DMA_INTR;
>     s->dmaregs[1] += len;
>  }
>
> @@ -179,9 +186,16 @@ static void dma_mem_writel(void *opaque, target_phys_addr_t addr, uint32_t val)
>             s->dmaregs[saddr], val);
>     switch (saddr) {
>     case 0:
> -        if (!(val & DMA_INTREN)) {
> -            DPRINTF("Lower IRQ\n");
> -            qemu_irq_lower(s->irq);
> +        if (val & DMA_INTREN) {
> +            if (val & DMA_INTR) {
> +                DPRINTF("Raise IRQ\n");
> +                qemu_irq_raise(s->irq);
> +            }
> +        } else {
> +            if (s->dmaregs[0] & (DMA_INTR | DMA_INTREN)) {
> +                DPRINTF("Lower IRQ\n");
> +                qemu_irq_lower(s->irq);
> +            }
>         }
>         if (val & DMA_RESET) {
>             qemu_irq_raise(s->dev_reset);
>