[PATCH] lib: sbi: Put event after use in sbi_sse_exit() loop

[Anup Patel]

On Thu, May 9, 2024 at 12:42 PM Anup Patel <apatel at ventanamicro.com> wrote:
>
> Currently, the sbi_sse_exit() gets event in a loop but does not put
> it back after use. This results in global events remaining locked
> causing hangs on sub-sequent calls to sse_event_get() for global
> events.
>
> Fixes: c8cdf01d8f3a ("lib: sbi: Add support for Supervisor Software Events extension")
> Signed-off-by: Anup Patel <apatel at ventanamicro.com>

Applied this patch to the riscv/opensbi repo.

Thanks,
Anup

> ---
>  lib/sbi/sbi_sse.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/lib/sbi/sbi_sse.c b/lib/sbi/sbi_sse.c
> index 18dfdb6..0cd6ba6 100644
> --- a/lib/sbi/sbi_sse.c
> +++ b/lib/sbi/sbi_sse.c
> @@ -1121,13 +1121,18 @@ void sbi_sse_exit(struct sbi_scratch *scratch)
>
>         for (i = 0; i < EVENT_COUNT; i++) {
>                 e = sse_event_get(supported_events[i]);
> -
> -               if (!e || e->attrs.hartid != current_hartid())
> +               if (!e)
>                         continue;
>
> +               if (e->attrs.hartid != current_hartid())
> +                       goto skip;
> +
>                 if (sse_event_state(e) > SBI_SSE_STATE_REGISTERED) {
>                         sbi_printf("Event %d in invalid state at exit", i);
>                         sse_event_set_state(e, SBI_SSE_STATE_UNUSED);
>                 }
> +
> +skip:
> +               sse_event_put(e);
>         }
>  }
> --
> 2.34.1
>