Return-path: Received: from mail-vw0-f46.google.com ([209.85.212.46]:36669 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751531Ab0LYVuz convert rfc822-to-8bit (ORCPT ); Sat, 25 Dec 2010 16:50:55 -0500 MIME-Version: 1.0 In-Reply-To: References: Date: Sat, 25 Dec 2010 22:50:52 +0100 Message-ID: Subject: Re: [linux-pm] subtle pm_runtime_put_sync race and sdio functions From: Vitaly Wool To: Ohad Ben-Cohen Cc: Alan Stern , linux-wireless@vger.kernel.org, linux-mmc@vger.kernel.org, Ido Yariv , linux-pm@lists.linux-foundation.org, Johannes Berg Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi Ohad, On Sat, Dec 25, 2010 at 9:58 PM, Ohad Ben-Cohen wrote: > On Sat, Dec 25, 2010 at 6:21 PM, Alan Stern wrote: >> Right. ?You may or may not realize it, but this requirement means that >> the driver _must_ bypass runtime PM sometimes. > > http://www.spinics.net/lists/linux-pm/msg22864.html > >> Now you've lost me. ?Which of the driver's handlers are you talking >> about? > > The driver's handler, which is called by mac80211, and is responsible > to power off the device. > The _same_ handler is being called either during runtime or during a > system transition to suspend > >> What races? > > Driver thinks power is off and device is now fully reset, but it's isn't really maybe it's worth starting off with the description of chip power states and how they are mapped to runtime PM and static PM? Most of the WLAN chips have some very low power modes, but you're talking about _complete_ shutdown as a suspended state for both runtime PM and static PM, is that correct? Thanks, Vitaly