From mboxrd@z Thu Jan 1 00:00:00 1970 From: vkalia@codeaurora.org Subject: Usage of notifier callback in devfreq Date: Fri, 13 Feb 2015 20:41:05 -0000 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]:34191 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752618AbbBMUlH (ORCPT ); Fri, 13 Feb 2015 15:41:07 -0500 Received: from www.codeaurora.org (unknown [198.145.29.65]) by smtp.codeaurora.org (Postfix) with ESMTP id A15A013FFE2 for ; Fri, 13 Feb 2015 20:41:05 +0000 (UTC) Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: linux-pm@vger.kernel.org Hi We want to implement DCVS for video device. Video device interrupts the driver when the frequency needs to be updated. Since conventional governors work on polling mechanism we would like to know how we can implement a governor with event based mechanism. We would like to use the notifier callback in devfreq for this to wake up the governor at certain points so it can query the new stats from video driver. Is this the right approach? If not can you please suggest an alternative. Any examples will be of great help. Notifier callback we plan to use is @ https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/devfreq/devfreq.c?id=refs/tags/v3.19#n480 Thanks Vinay