From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Tissoires Subject: Re: [PATCH v3] HID: i2c-hid: Fix suspend/resume when already runtime suspended Date: Wed, 9 Mar 2016 20:56:38 +0100 Message-ID: <20160309195638.GK22340@mail.corp.redhat.com> References: <20160308230323.GA4382@dtor-ws> <20160309120411.GF1796@lahna.fi.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <20160309120411.GF1796@lahna.fi.intel.com> Sender: linux-kernel-owner@vger.kernel.org To: Mika Westerberg Cc: Dmitry Torokhov , Jiri Kosina , Andrew Duggan , Benson Leung , Dan Carpenter , Gabriele Mazzotta , Doug Anderson , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, "Rafael J. Wysocki" List-Id: linux-input@vger.kernel.org On Mar 09 2016 or thereabouts, Mika Westerberg wrote: > On Tue, Mar 08, 2016 at 03:03:23PM -0800, Dmitry Torokhov wrote: > > On ACPI-based systems ACPI power domain code runtime resumes device before > > calling suspend method, which ensures that i2c-hid suspend code starts with > > device not in low-power state and with interrupts enabled. > > > > On other systems, especially if device is not a part of any power domain, > > we may end up calling driver's system-level suspend routine while the > > device is runtime-suspended (with controller in presumably low power state > > and interrupts disabled). This will result in interrupts being essentially > > disabled twice, and we will only re-enable them after both system resume > > and runtime resume methods complete. Unfortunately i2c_hid_resume() calls > > i2c_hid_hwreset() and that only works properly if interrupts are enabled. > > > > Also if device is runtime-suspended driver's suspend code may fail if it > > tries to issue I/O requests. > > > > Let's fix it by runtime-resuming the device if we need to run HID driver's > > suspend code and also disabling interrupts only if device is not already > > runtime-suspended. Also on resume we mark the device as running at full > > power (since that is what resetting will do to it). > > > > Signed-off-by: Doug Anderson > > Signed-off-by: Dmitry Torokhov > > Tested on a couple of Intel Skylake and Baytrail based systems and power > management of I2C connected HID devices still seems to work just fine. > > Tested-by: Mika Westerberg Well, I have completely no way of testing this myself, and I blindly trust Mika, Dmitry and the others for doing the right thing :). Acked-by: Benjamin Tissoires Cheers, Benjamin