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 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 193D1C282C0 for ; Fri, 25 Jan 2019 12:40:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DA1A72146E for ; Fri, 25 Jan 2019 12:40:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728445AbfAYMkj (ORCPT ); Fri, 25 Jan 2019 07:40:39 -0500 Received: from mx2.suse.de ([195.135.220.15]:37150 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726100AbfAYMkj (ORCPT ); Fri, 25 Jan 2019 07:40:39 -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 A3F38ACCF; Fri, 25 Jan 2019 12:40:37 +0000 (UTC) Date: Fri, 25 Jan 2019 13:40:37 +0100 Message-ID: From: Takashi Iwai To: Jon Hunter Cc: Sameer Pujar , , , , , , , Subject: Re: [PATCH] ALSA: hda/tegra: enable clock during probe In-Reply-To: <06c00ce1-32ed-8aa9-0340-d00202a8fa62@nvidia.com> References: <1548351403-1875-1-git-send-email-spujar@nvidia.com> <06c00ce1-32ed-8aa9-0340-d00202a8fa62@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 Fri, 25 Jan 2019 12:36:00 +0100, Jon Hunter wrote: > > > On 24/01/2019 19:08, Takashi Iwai wrote: > > On Thu, 24 Jan 2019 18:36:43 +0100, > > Sameer Pujar wrote: > >> > >> If CONFIG_PM is disabled or runtime PM calls are forbidden, the clocks > >> will not be ON. This could cause issue during probe, where hda init > >> setup is done. This patch checks whether runtime PM is enabled or not. > >> If disabled, clocks are enabled in probe() and disabled in remove() > >> > >> This patch does following minor changes as cleanup, > >> * return code check for pm_runtime_get_sync() to take care of failure > >> and exit gracefully. > >> * In remove path runtime PM is disabled before calling snd_card_free(). > >> * hda_tegra_disable_clocks() is moved out of CONFIG_PM_SLEEP check. > >> * runtime PM callbacks moved out of CONFIG_PM check > >> > >> Signed-off-by: Sameer Pujar > >> Reviewed-by: Ravindra Lokhande > >> Reviewed-by: Jon Hunter > > (snip) > >> @@ -555,6 +553,13 @@ static int hda_tegra_probe(struct platform_device *pdev) > >> if (!azx_has_pm_runtime(chip)) > >> pm_runtime_forbid(hda->dev); > >> > >> + /* explicit resume if runtime PM is disabled */ > >> + if (!pm_runtime_enabled(hda->dev)) { > >> + err = hda_tegra_runtime_resume(hda->dev); > >> + if (err) > >> + goto out_free; > >> + } > >> + > >> schedule_work(&hda->probe_work); > > > > Calling runtime_resume here is really confusing... > > Why? IMO it is better to have a single handler for resuming the device > and so if RPM is not enabled we call the handler directly. This is what > we have been advised to do in the past and do in other drivers. See ... The point is that we're not "resuming" anything there. It's in the early probe stage, and the device state is uninitialized, not really suspended. It'd end up with just calling the same helper (hda_tegra_enable_clocks()), though. Takashi