From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: RE: [PATCH] net: davinci_emac: Add pre_open, post_stop platform callbacks Date: Thu, 3 May 2012 21:22:22 +0100 Message-ID: <1336076542.2998.23.camel@bwh-desktop.uk.solarflarecom.com> References: <20120502234718.GA5432@animalcreek.com> <20120503160917.GA11310@animalcreek.com> <20120503184632.GA28089@animalcreek.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: "Mark A. Greer" , "netdev@vger.kernel.org" , "linux-omap@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" To: "Bedia, Vaibhav" Return-path: Received: from webmail.solarflare.com ([12.187.104.25]:30997 "EHLO ocex02.SolarFlarecom.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758539Ab2ECUW3 (ORCPT ); Thu, 3 May 2012 16:22:29 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 2012-05-03 at 19:25 +0000, Bedia, Vaibhav wrote: > On Fri, May 04, 2012 at 00:16:32, Mark A. Greer wrote: > [...] > > > > > > So, if I understood this correctly, it's effectively like blocking a low power > > > state transition (here wfi execution) when EMAC is active? > > > > Assuming "it" is my patch, correct. > > > > Recently I was thinking about how to get certain drivers to disallow some or all > low power states and to me this also seems to fall in a similar category. > > One of the suggestions that I got was to check if the 'wakeup' entry associated with > the device under sysfs could be leveraged for this. The PM code could maintain > a whitelist (or blacklist) of devices and it decides the low power state to enter > based on the 'wakeup' entries associated with these devices. In this particular case, > maybe the driver could simply set this entry to non-wakeup capable when necessary and > then let the PM code take care of skipping the wfi execution. > > Thoughts/brickbats welcome :) You can maybe (ab)use the pm_qos mechanism for this. Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.