linux-kernel - Re: [PATCH v3 1/5] PM / clock_ops: Add pm_clk_add

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:	Thu, 23 Oct 2014 08:49:28 -0700
From:	Dmitry Torokhov <dmitry.torokhov@...il.com>
To:	Grygorii Strashko <grygorii.strashko@...com>
Cc:	ssantosh@...nel.org, "Rafael J. Wysocki" <rjw@...ysocki.net>,
	khilman@...aro.org, linux-pm@...r.kernel.org,
	Rob Herring <robh+dt@...nel.org>, grant.likely@...retlab.ca,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	devicetree@...r.kernel.org,
	Geert Uytterhoeven <geert+renesas@...der.be>,
	Ulf Hansson <ulf.hansson@...aro.org>
Subject: Re: [PATCH v3 1/5] PM / clock_ops: Add pm_clk_add_clk()

On Thu, Oct 23, 2014 at 05:22:58PM +0300, Grygorii Strashko wrote:
> From: Geert Uytterhoeven <geert+renesas@...der.be>
> 
> The existing pm_clk_add() allows to pass a clock by con_id. However,
> when referring to a specific clock from DT, no con_id is available.
> 
> Add pm_clk_add_clk(), which allows to specify the struct clk * directly.
> 
> CC: Ulf Hansson <ulf.hansson@...aro.org>
> CC: Dmitry Torokhov <dmitry.torokhov@...il.com>
> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@...com>
> Reviewed-by: Kevin Hilman <khilman@...aro.org>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@...der.be>
> Signed-off-by: Grygorii Strashko <grygorii.strashko@...com>
> ---
>  drivers/base/power/clock_ops.c | 41 +++++++++++++++++++++++++++++++----------
>  include/linux/pm_clock.h       |  8 ++++++++
>  2 files changed, 39 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/base/power/clock_ops.c b/drivers/base/power/clock_ops.c
> index 7836930..f14b767 100644
> --- a/drivers/base/power/clock_ops.c
> +++ b/drivers/base/power/clock_ops.c
> @@ -53,7 +53,8 @@ static inline int __pm_clk_enable(struct device *dev, struct clk *clk)
>   */
>  static void pm_clk_acquire(struct device *dev, struct pm_clock_entry *ce)
>  {
> -	ce->clk = clk_get(dev, ce->con_id);
> +	if (!ce->clk)
> +		ce->clk = clk_get(dev, ce->con_id);
>  	if (IS_ERR(ce->clk)) {
>  		ce->status = PCE_STATUS_ERROR;
>  	} else {
> @@ -63,15 +64,8 @@ static void pm_clk_acquire(struct device *dev, struct pm_clock_entry *ce)
>  	}
>  }
>  
> -/**
> - * pm_clk_add - Start using a device clock for power management.
> - * @dev: Device whose clock is going to be used for power management.
> - * @con_id: Connection ID of the clock.
> - *
> - * Add the clock represented by @con_id to the list of clocks used for
> - * the power management of @dev.
> - */
> -int pm_clk_add(struct device *dev, const char *con_id)
> +static int __pm_clk_add(struct device *dev, const char *con_id,
> +			struct clk *clk)
>  {
>  	struct pm_subsys_data *psd = dev_to_psd(dev);
>  	struct pm_clock_entry *ce;
> @@ -93,6 +87,8 @@ int pm_clk_add(struct device *dev, const char *con_id)
>  			kfree(ce);
>  			return -ENOMEM;
>  		}
> +	} else {

You need __clk_get(clk) here, otherwise when you will be removing clocks
you'll be dropping a reference that does not belong to you (as yiou have
not taken it).

> +		ce->clk = clk;
>  	}
>  

Thanks.

-- 
Dmitry
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/