Re: [PATCH] soc: fsl: qe: fix static checker warning

[Li Yang]

On Wed, Aug 11, 2021 at 2:10 AM Maxim Kochetkov <fido_max@xxxxxxxx> wrote:
>
> The patch be7ecbd240b2: "soc: fsl: qe: convert QE interrupt
> controller to platform_device" from Aug 3, 2021, leads to the
> following static checker warning:
>
>         drivers/soc/fsl/qe/qe_ic.c:438 qe_ic_init()
>         warn: unsigned 'qe_ic->virq_low' is never less than zero.
>
> In old variant irq_of_parse_and_map() returns zero if failed so
> unsigned int for virq_high/virq_low was ok.
> In new variant platform_get_irq() returns negative error codes
> if failed so we need to use int for virq_high/virq_low.
>
> Also simplify high_handler checking and remove the curly braces
> to make checkpatch happy.
>
> Fixes: be7ecbd240b2 ("soc: fsl: qe: convert QE interrupt controller to platform_device")
> Signed-off-by: Maxim Kochetkov <fido_max@xxxxxxxx>
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> ---
>  drivers/soc/fsl/qe/qe_ic.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/soc/fsl/qe/qe_ic.c b/drivers/soc/fsl/qe/qe_ic.c
> index e710d554425d..bff34ee2150a 100644
> --- a/drivers/soc/fsl/qe/qe_ic.c
> +++ b/drivers/soc/fsl/qe/qe_ic.c
> @@ -54,8 +54,8 @@ struct qe_ic {
>         struct irq_chip hc_irq;
>
>         /* VIRQ numbers of QE high/low irqs */
> -       unsigned int virq_high;
> -       unsigned int virq_low;
> +       int virq_high;
> +       int virq_low;
>  };
>
>  /*
> @@ -435,9 +435,8 @@ static int qe_ic_init(struct platform_device *pdev)
>         qe_ic->virq_high = platform_get_irq(pdev, 0);
>         qe_ic->virq_low = platform_get_irq(pdev, 1);
>
> -       if (qe_ic->virq_low < 0) {
> +       if (qe_ic->virq_low < 0)

Probably should be <= 0 here.

>                 return -ENODEV;
> -       }
>
>         if (qe_ic->virq_high != qe_ic->virq_low) {

Probably we should check if qe_ic->virq_high > 0 here if we rely on
this to decide whether to set the handler later.

Applied with the above changes.  Thanks

>                 low_handler = qe_ic_cascade_low;
> @@ -459,7 +458,7 @@ static int qe_ic_init(struct platform_device *pdev)
>         irq_set_handler_data(qe_ic->virq_low, qe_ic);
>         irq_set_chained_handler(qe_ic->virq_low, low_handler);
>
> -       if (qe_ic->virq_high && qe_ic->virq_high != qe_ic->virq_low) {
> +       if (high_handler) {
>                 irq_set_handler_data(qe_ic->virq_high, qe_ic);
>                 irq_set_chained_handler(qe_ic->virq_high, high_handler);
>         }
> --
> 2.31.1
>