linux-kernel - Re: [PATCH V2] opp: Don't ignore clk

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:   Mon, 1 Feb 2021 22:54:45 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Viresh Kumar <viresh.kumar@...aro.org>,
        Viresh Kumar <vireshk@...nel.org>, Nishanth Menon <nm@...com>,
        Stephen Boyd <sboyd@...nel.org>
Cc:     linux-pm@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Rafael Wysocki <rjw@...ysocki.net>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH V2] opp: Don't ignore clk_get() errors other than -ENOENT

01.02.2021 07:22, Viresh Kumar пишет:
> Not all devices that need to use OPP core need to have clocks, a missing
> clock is fine in which case -ENOENT shall be returned by clk_get().
> 
> Anything else is an error and must be handled properly.
> 
> Reported-by: Dmitry Osipenko <digetx@...il.com>
> Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
> ---
> V2:
> - s/ENODEV/ENOENT
> - Use dev_err_probe()
> 
> Stephen, is the understanding correct that -ENOENT is the only error
> returned for missing clocks ?
> 
>  drivers/opp/core.c | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> index a518173fd64a..0beb3ee79523 100644
> --- a/drivers/opp/core.c
> +++ b/drivers/opp/core.c
> @@ -1252,6 +1252,8 @@ static struct opp_table *_update_opp_table_clk(struct device *dev,
>  					       struct opp_table *opp_table,
>  					       bool getclk)
>  {
> +	int ret;
> +
>  	/*
>  	 * Return early if we don't need to get clk or we have already tried it
>  	 * earlier.
> @@ -1261,18 +1263,19 @@ static struct opp_table *_update_opp_table_clk(struct device *dev,
>  
>  	/* Find clk for the device */
>  	opp_table->clk = clk_get(dev, NULL);
> -	if (IS_ERR(opp_table->clk)) {
> -		int ret = PTR_ERR(opp_table->clk);
>  
> -		if (ret == -EPROBE_DEFER) {
> -			dev_pm_opp_put_opp_table(opp_table);
> -			return ERR_PTR(ret);
> -		}
> +	ret = PTR_ERR_OR_ZERO(opp_table->clk);
> +	if (!ret)
> +		return opp_table;
>  
> +	if (ret == -ENOENT) {
>  		dev_dbg(dev, "%s: Couldn't find clock: %d\n", __func__, ret);
> +		return opp_table;
>  	}
>  
> -	return opp_table;
> +	dev_pm_opp_put_opp_table(opp_table);
> +
> +	return ERR_PTR(dev_err_probe(dev, ret, "Couldn't find clock\n"));
>  }
>  
>  /*
> 

Thanks, looks okay.

Although, I think the previous variant of coding style was a bit more appropriate, i.e. like this:

dev_err_probe(dev, "%s: Couldn't find clock: %d\n", __func__, ret);

return ERR_PTR(ret);