Re: [RFT][PATCH v2 2/2] PM / QoS: Fix device resume latency framework

From: Reinette Chatre <reinette.chatre@intel.com>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Linux PM <linux-pm@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Tero Kristo <t-kristo@ti.com>,
	Ramesh Thomas <ramesh.thomas@intel.com>,
	Alex Shi <alex.shi@linaro.org>
Subject: Re: [RFT][PATCH v2 2/2] PM / QoS: Fix device resume latency framework
Date: Fri, 3 Nov 2017 09:39:08 -0700	[thread overview]
Message-ID: <aea02edb-b112-18db-6de5-f10e9a43846d@intel.com> (raw)
In-Reply-To: <36826935.bDl2WuZxgq@aspire.rjw.lan>

Hi Rafael,

I started to test this but found myself triggering one of the warnings:

On 11/3/2017 4:50 AM, Rafael J. Wysocki wrote:
> --- linux-pm.orig/include/linux/pm_qos.h
> +++ linux-pm/include/linux/pm_qos.h
> @@ -28,16 +28,19 @@ enum pm_qos_flags_status {
>  	PM_QOS_FLAGS_ALL,
>  };
>  
> -#define PM_QOS_DEFAULT_VALUE -1
> +#define PM_QOS_DEFAULT_VALUE	(-1)

PM_QOS_DEFAULT_VALUE is -1 ...

> ===================================================================
> --- linux-pm.orig/drivers/base/power/qos.c
> +++ linux-pm/drivers/base/power/qos.c
> @@ -139,6 +139,9 @@ static int apply_constraint(struct dev_p
>  
>  	switch(req->type) {
>  	case DEV_PM_QOS_RESUME_LATENCY:
> +		if (WARN_ON(value < 0))
> +			value = 0;
> +

... causing me to hit this WARN_ON because apply_constraint() is called by __dev_pm_qos_remove_request() with the value parameter set to PM_QOS_DEFAULT_VALUE.

Reinette