Re: [PATCH v2 2/3] irqchip: Add the Sophgo SG2042 MSI interrupt controller

[Chen Wang <unicorn_wang@xxxxxxxxxxx>]

On 2024/12/11 7:13, Samuel Holland wrote:
> On 2024-12-09 1:12 AM, Chen Wang wrote:
[......]
> > +
> > +static int sg2042_msi_allocate_hwirq(struct sg2042_msi_data *priv, int num_req)
> > +{
> > +	int first;
> > +
> > +	guard(mutex)(&priv->msi_map_lock);
> > +	first = bitmap_find_free_region(priv->msi_map, priv->num_irqs,
> > +					get_count_order(num_req));
> > +	return first >= 0 ? priv->irq_first + first : -ENOSPC;
> How does this work? The irqdomain is instantiated with size == priv->num_irqs,
> so hwirqs must be less than priv->num_irqs. It also quite simplifies the code
> for hwirq be a number between 0 and priv->num_irqs. You only need to apply the
> offset when allocating the parent IRQ:
>
> 	fwspec.param[0] = priv->irq_first + hwirq;

I will double check, seems this need to be improved.

Thanks,

Chen

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