From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 407CFC282C3 for ; Thu, 24 Jan 2019 19:12:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 08A04218B0 for ; Thu, 24 Jan 2019 19:12:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729175AbfAXTMn (ORCPT ); Thu, 24 Jan 2019 14:12:43 -0500 Received: from mx2.suse.de ([195.135.220.15]:34812 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725909AbfAXTMn (ORCPT ); Thu, 24 Jan 2019 14:12:43 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id E9C98AE52; Thu, 24 Jan 2019 19:12:41 +0000 (UTC) Date: Thu, 24 Jan 2019 20:12:41 +0100 Message-ID: From: Takashi Iwai To: Sameer Pujar Cc: , , , Subject: Re: [PATCH] ALSA: hda: runtime PM is always active In-Reply-To: <3475c359-34ce-c04b-24dc-79458b2b3e2a@nvidia.com> References: <1548345432-11449-1-git-send-email-spujar@nvidia.com> <770a8e0e-3e20-6997-3342-98a3656e14c1@nvidia.com> <3475c359-34ce-c04b-24dc-79458b2b3e2a@nvidia.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 24 Jan 2019 20:01:13 +0100, Sameer Pujar wrote: > > > On 1/25/2019 12:13 AM, Takashi Iwai wrote: > > On Thu, 24 Jan 2019 19:15:12 +0100, > > Sameer Pujar wrote: > >> > >> On 1/24/2019 9:34 PM, Takashi Iwai wrote: > >>> On Thu, 24 Jan 2019 16:57:11 +0100, > >>> Sameer Pujar wrote: > >>>> The runtime PM count is incremented and set to active during hda codec > >>>> device init, but it is decremented and set to suspend during exit only. > >>>> Hence the runtime PM status is always active and hda device cannot be > >>>> put to runtime suspend. Keeping device usage active for entire period, > >>>> though nothing really happening on the device, seems unnecessary. > >>>> > >>>> This patch avoides incrementing runtime PM usage count of the device. > >>>> > >>>> Signed-off-by: Sameer Pujar > >>>> Reviewed-by: Ravindra Lokhande > >>>> Reviewed-by: Mohan Kumar D > >>> This breaks the existing things, I'm afraid. > >>> Did you really test and verify the behavior...? > >>> > >>> The runtime PM refcount is decremented at snd_hda_codec_register(), > >>> and that's the place to let runtime suspend of the codec really > >>> effective. (It's not about the controller, though.) > >>> > >> It worked fine at my end. I could put the device to runtime suspend > >> and resume it back multiple times. > >> Since you are suggesting it could break things, let me rework on the > >> patch and dig up a little more to > >> see if there is better way to fix this. > > Well, I don't see what you want to "fix". Do you see any bug? > I was expecting the device to be runtime suspended, once probe is > finished, until I playback something on it. > But it appears that rutntime PM is always active and runtime PM > suspend callback never happens. Does the behavior really appear? If so, it's a bug. The current design is to enable the runtime PM *after* the device registration. Otherwise it makes no sense -- the problem doesn't finish yet before that point. thanks, Takashi