Re: [Qemu-devel] [PATCH for-2.10 2/3] target/mips: Drop redundant gen_io_start/stop()

[Philippe Mathieu-Daudé]

On 08/02/2017 06:59 AM, James Hogan wrote:
> DMTC0 CP0_Cause does a redundant gen_io_start() and gen_io_end() pair,
> even though this is done for all DMTC0 operations outside of the switch
> statement. Remove these redundant calls.
>
> Fixes: 5dc5d9f055c5 ("mips: more fixes to the MIPS interrupt glue logic")
> Signed-off-by: James Hogan <address@hidden>

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

> Cc: Yongbok Kim <address@hidden>
> Cc: Aurelien Jarno <address@hidden>
> ---
>   target/mips/translate.c | 8 --------
>   1 file changed, 0 insertions(+), 8 deletions(-)
>
> diff --git a/target/mips/translate.c b/target/mips/translate.c
> index 6b41f7b65e00..6e724ac71dcd 100644
> --- a/target/mips/translate.c
> +++ b/target/mips/translate.c
> @@ -7403,15 +7403,7 @@ static void gen_dmtc0(DisasContext *ctx, TCGv arg, int 
> reg, int sel)
>           switch (sel) {
>           case 0:
>               save_cpu_state(ctx, 1);
> -            /* Mark as an IO operation because we may trigger a software
> -               interrupt.  */
> -            if (ctx->tb->cflags & CF_USE_ICOUNT) {
> -                gen_io_start();
> -            }
>               gen_helper_mtc0_cause(cpu_env, arg);
> -            if (ctx->tb->cflags & CF_USE_ICOUNT) {
> -                gen_io_end();
> -            }
>               /* Stop translation as we may have triggered an intetrupt. BS_STOP
>                * isn't sufficient, we need to ensure we break out of translated
>                * code to check for pending interrupts.  */