Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760334Ab3CIDAX (ORCPT ); Fri, 8 Mar 2013 22:00:23 -0500 Received: from mail-pb0-f42.google.com ([209.85.160.42]:55351 "EHLO mail-pb0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760233Ab3CIDAV (ORCPT ); Fri, 8 Mar 2013 22:00:21 -0500 Message-ID: <513AA5C0.2020604@linaro.org> Date: Sat, 09 Mar 2013 04:00:16 +0100 From: Daniel Lezcano User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130221 Thunderbird/17.0.3 MIME-Version: 1.0 To: Chuansheng Liu CC: lenb@kernel.org, len.brown@intel.com, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/3] intel_idle: Removing the redundant calculating for dev->state_count References: <1362674529.31506.17.camel@cliu38-desktop-build> <1362754926.31506.42.camel@cliu38-desktop-build> <1362755074.31506.45.camel@cliu38-desktop-build> In-Reply-To: <1362755074.31506.45.camel@cliu38-desktop-build> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2452 Lines: 74 On 03/08/2013 04:04 PM, Chuansheng Liu wrote: > > In function intel_idle_cpu_init() and intel_idle_cpuidle_driver_init(), > they are having the same for(;;) loop. > > Here in intel_idle_cpu_init(), the dev->state_count can be assigned by > drv->state_count directly. > > Signed-off-by: liu chuansheng > --- > drivers/idle/intel_idle.c | 30 ++---------------------------- > 1 files changed, 2 insertions(+), 28 deletions(-) > > diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c > index 17c9cf9..503b401 100644 > --- a/drivers/idle/intel_idle.c > +++ b/drivers/idle/intel_idle.c > @@ -599,38 +599,12 @@ static int intel_idle_cpuidle_driver_init(void) > */ > static int intel_idle_cpu_init(int cpu) > { > - int cstate; > struct cpuidle_device *dev; > + struct cpuidle_driver *drv = &intel_idle_driver; > > dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu); > > - dev->state_count = 1; > - > - for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) { > - int num_substates, mwait_hint, mwait_cstate, mwait_substate; > - > - if (cpuidle_state_table[cstate].enter == NULL) > - break; > - > - if (cstate + 1 > max_cstate) { > - printk(PREFIX "max_cstate %d reached\n", max_cstate); > - break; > - } > - > - mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags); > - mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint); > - mwait_substate = MWAIT_HINT2SUBSTATE(mwait_hint); > - > - /* does the state exist in CPUID.MWAIT? */ > - num_substates = (mwait_substates >> ((mwait_cstate + 1) * 4)) > - & MWAIT_SUBSTATE_MASK; > - > - /* if sub-state in table is not enumerated by CPUID */ > - if ((mwait_substate + 1) > num_substates) > - continue; > - > - dev->state_count += 1; > - } > + dev->state_count = drv->state_count; The cpuidle_register_device function already does this initialization. Probably you can get rid of this initialization and certainly factor out a bit the code in this case. -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/