[PATCH 1/7] Revert "riscv: Clear pending interrupts before enabling IPIs"

[Bin Meng]

On Fri, Sep 11, 2020 at 6:22 PM Sean Anderson <seanga2 at gmail.com> wrote:
>
> On 9/11/20 3:38 AM, Bin Meng wrote:
> > Hi Sean,
> >
> > On Tue, Sep 8, 2020 at 2:17 AM Sean Anderson <seanga2 at gmail.com> wrote:
> >>
> >> Clearing MIP doesn't do anything. Whoops. The following commits should
> >
> > Which following commits?
> >
> >> tackle this problem in a more robust manner.
> >>
> >> This reverts commit 9472630337e7c4ac442066b5a752aaa8c3b4d4a6.
> >>
> >> Signed-off-by: Sean Anderson <seanga2 at gmail.com>
> >> ---
> >>
> >>  arch/riscv/cpu/start.S | 2 --
> >>  1 file changed, 2 deletions(-)
> >>
> >> diff --git a/arch/riscv/cpu/start.S b/arch/riscv/cpu/start.S
> >> index bf9fdf369b..e3222b1ea7 100644
> >> --- a/arch/riscv/cpu/start.S
> >> +++ b/arch/riscv/cpu/start.S
> >> @@ -65,8 +65,6 @@ _start:
> >>  #else
> >>         li      t0, SIE_SSIE
> >>  #endif
> >> -       /* Clear any pending IPIs */
> >> -       csrc    MODE_PREFIX(ip), t0
> >
> > Did you mean the clearing MIP.MSIP actually does nothing, but the
> > following commit is the correct fix?
>
> Yes, but we also need

Is MIP.MSIP read-only on K210?

>
> [PATCH 3/7] riscv: Use NULL as a sentinel value for smp_call_function
>
> so the secondary harts know not to take any IPIs not raised by U-Boot.
>
> >
> > commit 40686c394e533fec765fe237936e353c84e73fff
> > Author: Sean Anderson <seanga2 at gmail.com>
> > Date:   Wed Jun 24 06:41:18 2020 -0400
> >
> >     riscv: Clean up IPI initialization code
> >
> >     The previous IPI code initialized the device whenever the first call was
> >     made to a riscv_*_ipi function. This made it difficult to determine when
> >     the IPI device was initialized. This patch introduces a new function
> >     riscv_init_ipi. It is called once during arch_cpu_init_dm. In SPL, it is
> >     called in spl_invoke_opensbi. Before this point, no riscv_*_ipi functions
> >     should be called.
> >
> >     Signed-off-by: Sean Anderson <seanga2 at gmail.com>
> >     Reviewed-by: Rick Chen <rick at andestech.com>
> >
> >>         csrs    MODE_PREFIX(ie), t0
> >>  #endif

Regards,
Bin