From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nishanth Menon Subject: Re: [PATCH 01/13] OMAP: Introduce a user list for each voltage domain instance in the voltage driver. Date: Thu, 2 Sep 2010 05:40:56 -0500 Message-ID: <4C7F7F38.1050709@ti.com> References: <1282130412-12027-1-git-send-email-thara@ti.com> <1282130412-12027-2-git-send-email-thara@ti.com> <87eiddgjr7.fsf@deeprootsystems.com> <20100902094327.31a96174@surf> <4C7F5DB4.70306@ti.com> <38353bada7f16740e8008e6d3f2748bd@secure211.sgcpanel.com> <4C7F799D.8020207@ti.com> <2aa29e22fb1502b14ac7850a12e68e5b@secure211.sgcpanel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from devils.ext.ti.com ([198.47.26.153]:55927 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752165Ab0IBKlH (ORCPT ); Thu, 2 Sep 2010 06:41:07 -0400 In-Reply-To: <2aa29e22fb1502b14ac7850a12e68e5b@secure211.sgcpanel.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Felipe Balbi Cc: Thomas Petazzoni , Kevin Hilman , "Gopinath, Thara" , "linux-omap@vger.kernel.org" , "paul@pwsan.com" , "Sripathy, Vishwanath" , "Sawant, Anand" , "Cousson, Benoit" Felipe Balbi had written, on 09/02/2010 05:28 AM, the following: > Hi, > > On Thu, 2 Sep 2010 05:17:01 -0500, Nishanth Menon wrote: >> note - if we allow unlock of irqs at this point, we cannot predictably >> progress down the logic. > > spin_unlock() would not re-enable IRQs, would it ? Isn't it so that > spin_unlock_irq() would be the one re-enabling IRQ ? > oopss.. my bad.. if we were to do regulator based implementation of voltage framework, looking closer at the code, driver/regulator/core.c -> rdev->mutex is held for set_voltage, set_mode and all entry functions for regulator operations -> this would be the only concern i have.. I may be barking up the wrong tree here, but i think if i read Documentation/mutex-design.txt right, "contexts such as tasklets and timers" and "mutexes may not be used in hardware or software interrupt" means to me dont do this in irq locked context such as the sitn in omap_sram_idle? -- Regards, Nishanth Menon