Re: [PATCH net 01/10] net: pse-pd: size the notification kfifo after defaulting nr_lines

[Kory Maincent <kory.maincent@bootlin.com>]

On 10/18/26 10:23, Carlo Szelinsky wrote:
> pse_controller_register() allocates the notification kfifo before it
> turns nr_lines == 0 into 1, and kfifo_alloc() fails for a size below 2.
> So a controller with nr_lines 0 or 1 cannot register. pse_regulator
> (podl-pse-regulator) never sets nr_lines, so its probe has failed with
> -EINVAL ever since the kfifo was added.
> 
> Apply the default first, and allocate at least two entries.

Reviewed-by: Kory Maincent <kory.maincent@bootlin.com>

Thank you!

> Fixes: ffef61d6d273 ("net: pse-pd: Add support for budget evaluation strategies")
> Signed-off-by: Carlo Szelinsky <github@szelinsky.de>
> ---
>   drivers/net/pse-pd/pse_core.c | 11 +++++++----
>   1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/pse-pd/pse_core.c b/drivers/net/pse-pd/pse_core.c
> index a5e6d7b26b9f..c0573cbbba5b 100644
> --- a/drivers/net/pse-pd/pse_core.c
> +++ b/drivers/net/pse-pd/pse_core.c
> @@ -1044,16 +1044,19 @@ int pse_controller_register(struct pse_controller_dev *pcdev)
>   	mutex_init(&pcdev->lock);
>   	INIT_LIST_HEAD(&pcdev->pse_control_head);
>   	spin_lock_init(&pcdev->ntf_fifo_lock);
> -	ret = kfifo_alloc(&pcdev->ntf_fifo, pcdev->nr_lines, GFP_KERNEL);
> +
> +	if (!pcdev->nr_lines)
> +		pcdev->nr_lines = 1;
> +
> +	/* kfifo_alloc() rejects a size that rounds up to less than 2 */
> +	ret = kfifo_alloc(&pcdev->ntf_fifo, max(pcdev->nr_lines, 2U),
> +			  GFP_KERNEL);
>   	if (ret) {
>   		dev_err(pcdev->dev, "failed to allocate kfifo notifications\n");
>   		return ret;
>   	}
>   	INIT_WORK(&pcdev->ntf_work, pse_send_ntf_worker);
>   
> -	if (!pcdev->nr_lines)
> -		pcdev->nr_lines = 1;
> -
>   	if (!pcdev->ops->pi_get_admin_state ||
>   	    !pcdev->ops->pi_get_pw_status) {
>   		dev_err(pcdev->dev,

-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com