Re: [PATCH] irqchip/sifive-plic: Fix error codes

[Alexandre Ghiti]

Hi Charlie,

On 04/09/2024 01:36, Charlie Jenkins wrote:
> Set error to -ENOMEM if kcalloc() fails or if irq_domain_add_linear()
> fails inside of plic_probe().
>
> Signed-off-by: Charlie Jenkins <charlie@xxxxxxxxxxxx>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Closes: https://lore.kernel.org/r/202409031122.yBh8HrxA-lkp@xxxxxxxxx/


I found the following Fixes tag:

Fixes: 4d936f10ff80 ("irqchip/sifive-plic: Probe plic driver early for 
Allwinner D1 platform")


> ---
>   drivers/irqchip/irq-sifive-plic.c | 8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
> index 2f6ef5c495bd..0b730e305748 100644
> --- a/drivers/irqchip/irq-sifive-plic.c
> +++ b/drivers/irqchip/irq-sifive-plic.c
> @@ -626,8 +626,10 @@ static int plic_probe(struct fwnode_handle *fwnode)
>   
>   		handler->enable_save = kcalloc(DIV_ROUND_UP(nr_irqs, 32),
>   					       sizeof(*handler->enable_save), GFP_KERNEL);
> -		if (!handler->enable_save)
> +		if (!handler->enable_save) {
> +			error = -ENOMEM;


This is correct.


>   			goto fail_cleanup_contexts;
> +		}
>   done:
>   		for (hwirq = 1; hwirq <= nr_irqs; hwirq++) {
>   			plic_toggle(handler, hwirq, 0);
> @@ -639,8 +641,10 @@ static int plic_probe(struct fwnode_handle *fwnode)
>   
>   	priv->irqdomain = irq_domain_create_linear(fwnode, nr_irqs + 1,
>   						   &plic_irqdomain_ops, priv);
> -	if (WARN_ON(!priv->irqdomain))
> +	if (WARN_ON(!priv->irqdomain)) {
> +		error = -ENOMEM;


Here though I found drivers that return either ENODEV 
(https://elixir.bootlin.com/linux/v6.11/source/drivers/irqchip/irq-gic.c#L1210) 
or ENOMEM 
(https://elixir.bootlin.com/linux/v6.11/source/drivers/irqchip/irq-imx-mu-msi.c#L229).

Before the commit I mentioned above, we used to return ENOMEM. IMHO it's 
not a big deal as long as we return something different from 0 in that 
case, I just mention it if someone thinks differently.

You can add:

Reviewed-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>

And I would also add:

Cc: stable@xxxxxxxxxxxxxxx

Thanks,

Alex


>   		goto fail_cleanup_contexts;
> +	}
>   
>   	/*
>   	 * We can have multiple PLIC instances so setup global state
>
> ---
> base-commit: 6804f0edbe7747774e6ae60f20cec4ee3ad7c187
> change-id: 20240903-correct_error_codes_sifive_plic-4611f59291df