[PATCH 2/2] lib: sbi_hsm: Use csr_set to restore the MIP

[Anup Patel]

On Tue, Jan 17, 2023 at 1:44 PM Nick Hu <nick.hu at sifive.com> wrote:
>
> If we use the csr_write to restore the MIP, we may clear the SEIP.
> In generic behavior of QEMU, if the pending bits of PLIC are set and we
> clear the SEIP, the QEMU may not set it back immediately. It may cause
> the interrupts won't be handled anymore until the new interrupts arrived
> and QEMU set the bits back.
>
> Signed-off-by: Nick Hu <nick.hu at sifive.com>
> Signed-off-by: Jim Shu <jim.shu at sifive.com>

Looks good to me.

Reviewed-by: Anup Patel <anup at brainfault.org>

Regards,
Anup

> ---
>  lib/sbi/sbi_hsm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/sbi/sbi_hsm.c b/lib/sbi/sbi_hsm.c
> index c0a5505..39cd1ab 100644
> --- a/lib/sbi/sbi_hsm.c
> +++ b/lib/sbi/sbi_hsm.c
> @@ -358,7 +358,7 @@ static void __sbi_hsm_suspend_non_ret_restore(struct sbi_scratch *scratch)
>                                                             hart_data_offset);
>
>         csr_write(CSR_MIE, hdata->saved_mie);
> -       csr_write(CSR_MIP, (hdata->saved_mip & (MIP_SSIP | MIP_STIP)));
> +       csr_set(CSR_MIP, (hdata->saved_mip & (MIP_SSIP | MIP_STIP)));
>  }
>
>  void sbi_hsm_hart_resume_start(struct sbi_scratch *scratch)
> --
> 2.34.1
>
>
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