From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e36.co.us.ibm.com (e36.co.us.ibm.com [32.97.110.154]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 02BBD1A0C2A for ; Wed, 28 Jan 2015 20:50:45 +1100 (AEDT) Received: from /spool/local by e36.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 28 Jan 2015 02:50:43 -0700 Received: from b03cxnp08027.gho.boulder.ibm.com (b03cxnp08027.gho.boulder.ibm.com [9.17.130.19]) by d03dlp02.boulder.ibm.com (Postfix) with ESMTP id 8073F3E4003E for ; Wed, 28 Jan 2015 02:50:40 -0700 (MST) Received: from d03av05.boulder.ibm.com (d03av05.boulder.ibm.com [9.17.195.85]) by b03cxnp08027.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t0S9oeka34734198 for ; Wed, 28 Jan 2015 02:50:40 -0700 Received: from d03av05.boulder.ibm.com (localhost [127.0.0.1]) by d03av05.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t0S9odms011435 for ; Wed, 28 Jan 2015 02:50:40 -0700 Message-ID: <54C8B0E6.5080406@linux.vnet.ibm.com> Date: Wed, 28 Jan 2015 15:20:30 +0530 From: Preeti U Murthy MIME-Version: 1.0 To: Stewart Smith , mpe@ellerman.id.au Subject: Re: [PATCH V2] cpuidle/powernv: Read target_residency value of idle states from DT if available References: <20150128021044.11166.81418.stgit@preeti.in.ibm.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Cc: rafael.j.wysocki@intel.com, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 01/28/2015 02:45 PM, Stewart Smith wrote: > Preeti U Murthy writes: >> The device tree now exposes the residency values for different idle states. Read >> these values instead of calculating residency from the latency values. The values >> exposed in the DT are validated for optimal power efficiency. However to maintain >> compatibility with the older firmware code which does not expose residency >> values, use default values as a fallback mechanism. While at it, handle some >> cleanups. > > From a "I just merged the patch that exports these values from firmware" > point of view, using them and falling back looks good. > > (I find the hardcoding of snooze in the driver a bit odd, as is the Snooze is the only software defined idle state, the rest are platform specific. The first idle state is usually associated with some sort of a polling operation and each architecture has a variant to this. This is why we end up hard-coding this idle state in the driver as far as my understanding goes. > hardcoding of max power states to 8 - which could bite us in the future Hmm.. not sure about this. Need to check. > if a future processor has more states... but these aren't problems with > this patch) > > Acked-by: Stewart Smith Thanks! Regards Preeti U Murthy >