linux-kernel - Re: [PATCH] clk: qcom: clk-rpmh: Fix if statement to match comment

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20220610195856.A2D7EC3411C@smtp.kernel.org>
Date:   Fri, 10 Jun 2022 12:58:54 -0700
From:   Stephen Boyd <sboyd@...nel.org>
To:     Li Zhengyu <lizhengyu3@...wei.com>, quic_tdas@...cinc.com
Cc:     agross@...nel.org, bjorn.andersson@...aro.org,
        linux-arm-msm@...r.kernel.org, linux-clk@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] clk: qcom: clk-rpmh: Fix if statement to match comment

Quoting Li Zhengyu (2022-05-31 02:45:39)
> (c->state) is u32, (enable) is bool. It returns false when
> (c->state) > 1 and (enable) is true. Convert (c->state) to bool.
> 
> Signed-off-by: Li Zhengyu <lizhengyu3@...wei.com>

Nice catch! It looks like it fixes an optimization, where we don't want
to run through and check has_state_changed() if this clk is already
enabled or disabled. But how does this ever happen? The clk framework
already reference counts prepare/unprepare, so how can we get into this
function when the condition would be true, after this patch?

I think we can simply remove the if condition entirely. Do you agree?

> ---
>  drivers/clk/qcom/clk-rpmh.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/qcom/clk-rpmh.c b/drivers/clk/qcom/clk-rpmh.c
> index aed907982344..851e127432a9 100644
> --- a/drivers/clk/qcom/clk-rpmh.c
> +++ b/drivers/clk/qcom/clk-rpmh.c
> @@ -196,7 +196,7 @@ static int clk_rpmh_aggregate_state_send_command(struct clk_rpmh *c,
>         int ret;
>  
>         /* Nothing required to be done if already off or on */
> -       if (enable == c->state)
> +       if (enable == !!c->state)
>                 return 0;
>  
>         c->state = enable ? c->valid_state_mask : 0;