Re: [PATCH] IB/hfi1: Fix logical condition in msix_request_irq

[Nick Desaulniers]

On Thu, Jan 16, 2020 at 2:27 PM Nathan Chancellor
<natechancellor@xxxxxxxxx> wrote:
>
> Clang warns:
>
> drivers/infiniband/hw/hfi1/msix.c:136:22: warning: overlapping
> comparisons always evaluate to false [-Wtautological-overlap-compare]
>         if (type < IRQ_SDMA && type >= IRQ_OTHER)
>             ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~
> 1 warning generated.
>
> It is impossible for something to be less than 0 (IRQ_SDMA) and greater
> than or equal to 3 (IRQ_OTHER) at the same time. A logical OR should
> have been used to keep the same logic as before.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/841
> Fixes: 13d2a8384bd9 ("IB/hfi1: Decouple IRQ name from type")
> Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>

Thanks for the patch. LGTM.
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>

> ---
>  drivers/infiniband/hw/hfi1/msix.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/infiniband/hw/hfi1/msix.c b/drivers/infiniband/hw/hfi1/msix.c
> index 4a620cf80588..db82db497b2c 100644
> --- a/drivers/infiniband/hw/hfi1/msix.c
> +++ b/drivers/infiniband/hw/hfi1/msix.c
> @@ -133,7 +133,7 @@ static int msix_request_irq(struct hfi1_devdata *dd, void *arg,
>         if (nr == dd->msix_info.max_requested)
>                 return -ENOSPC;
>
> -       if (type < IRQ_SDMA && type >= IRQ_OTHER)
> +       if (type < IRQ_SDMA || type >= IRQ_OTHER)

-- 
Thanks,
~Nick Desaulniers