linux-kernel - Re: [PATCH v3 2/3] soc: rockchip: power-domain: Replace dsb() with smb()

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Message-ID: <CAMdYzYqyDr1HFYB4p8NK8ssq60qfjR2jyoSJ=tcRn8CWsZr16g@mail.gmail.com>
Date:   Tue, 26 Apr 2022 19:55:02 -0400
From:   Peter Geis <pgwipeout@...il.com>
To:     Brian Norris <briannorris@...omium.org>
Cc:     Heiko Stuebner <heiko@...ech.de>, Arnd Bergmann <arnd@...db.de>,
        Robin Murphy <robin.murphy@....com>,
        "open list:ARM/Rockchip SoC..." <linux-rockchip@...ts.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Guenter Roeck <linux@...ck-us.net>
Subject: Re: [PATCH v3 2/3] soc: rockchip: power-domain: Replace dsb() with smb()

On Mon, Apr 25, 2022 at 9:46 PM Brian Norris <briannorris@...omium.org> wrote:
>
> It's unclear if these are really needed at all, but seemingly their
> purpose is only as a write barrier. Use the general macro instead of the
> ARM-specific one.
>
> This driver is partially marked for COMPILE_TEST'ing, but it doesn't
> build under non-ARM architectures. Fix this up before *really* enabling
> it for COMPILE_TEST.
>
> Signed-off-by: Brian Norris <briannorris@...omium.org>
> ---
>
> Changes in v3:
>  * New in v3
>
>  drivers/soc/rockchip/pm_domains.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/soc/rockchip/pm_domains.c b/drivers/soc/rockchip/pm_domains.c
> index 1b029e494274..cf16ff9b73b3 100644
> --- a/drivers/soc/rockchip/pm_domains.c
> +++ b/drivers/soc/rockchip/pm_domains.c
> @@ -178,7 +178,7 @@ static int rockchip_pmu_set_idle_request(struct rockchip_pm_domain *pd,
>                 regmap_update_bits(pmu->regmap, pmu->info->req_offset,
>                                    pd_info->req_mask, idle ? -1U : 0);
>
> -       dsb(sy);
> +       wmb();

Just curious, shouldn't this be mb() instead of wmb()?
>From the arm64 barrier.h:

#define mb() dsb(sy)
#define wmb() dsb(st)


>
>         /* Wait util idle_ack = 1 */
>         target_ack = idle ? pd_info->ack_mask : 0;
> @@ -285,7 +285,7 @@ static void rockchip_do_pmu_set_power_domain(struct rockchip_pm_domain *pd,
>                 regmap_update_bits(pmu->regmap, pmu->info->pwr_offset,
>                                    pd->info->pwr_mask, on ? 0 : -1U);
>
> -       dsb(sy);
> +       wmb();
>
>         if (readx_poll_timeout_atomic(rockchip_pmu_domain_is_on, pd, is_on,
>                                       is_on == on, 0, 10000)) {
> --
> 2.36.0.rc2.479.g8af0fa9b8e-goog
>
>
> _______________________________________________
> Linux-rockchip mailing list
> Linux-rockchip@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-rockchip

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