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=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 41575C433DB for ; Mon, 21 Dec 2020 16:48:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 03E5A22525 for ; Mon, 21 Dec 2020 16:48:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725875AbgLUQsc (ORCPT ); Mon, 21 Dec 2020 11:48:32 -0500 Received: from mx2.suse.de ([195.135.220.15]:48198 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725777AbgLUQsc (ORCPT ); Mon, 21 Dec 2020 11:48:32 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 41CFDAD35; Mon, 21 Dec 2020 16:47:50 +0000 (UTC) Date: Mon, 21 Dec 2020 17:47:49 +0100 Message-ID: From: Takashi Iwai To: Kai-Heng Feng Cc: tiwai@suse.com, Jaroslav Kysela , Kai Vehmanen , Pierre-Louis Bossart , Alex Deucher , Mike Rapoport , "moderated list:SOUND" , open list , Bjorn Helgaas , Alan Stern , Linux PCI , nouveau@lists.freedesktop.org Subject: Re: [PATCH v2] ALSA: hda: Continue to probe when codec probe fails In-Reply-To: References: <20201214060621.1102931-1-kai.heng.feng@canonical.com> <20201216124726.2842197-1-kai.heng.feng@canonical.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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 21 Dec 2020 17:33:20 +0100, Kai-Heng Feng wrote: > > [+Cc nouveau] > > On Fri, Dec 18, 2020 at 4:06 PM Takashi Iwai wrote: > [snip] > > > Quite possibly the system doesn't power up HDA controller when there's > > > no external monitor. > > > So when it's connected to external monitor, it's still needed for HDMI audio. > > > Let me ask the user to confirm this. > > > > Yeah, it's the basic question whether the HD-audio is supposed to work > > on this machine at all. If yes, the current approach we take makes > > less sense - instead we should rather make the HD-audio controller > > working. > > Yea, confirmed that the Nvidia HDA works when HDMI is connected prior boot. > > > > > - The second problem is that pci_enable_device() ignores the error > > > > returned from pci_set_power_state() if it's -EIO. And the > > > > inaccessible access error returns -EIO, although it's rather a fatal > > > > problem. So the driver believes as the PCI device gets enabled > > > > properly. > > > > > > This was introduced in 2005, by Alan's 11f3859b1e85 ("[PATCH] PCI: Fix > > > regression in pci_enable_device_bars") to fix UHCI controller. > > > > > > > > > > > - The third problem is that HD-audio driver blindly believes the > > > > codec_mask read from the register even if it's a read failure as I > > > > already showed. > > > > > > This approach has least regression risk. > > > > Yes, but it assumes that HD-audio is really non-existent. > > I really don't know any good approach to address this. > On Windows, HDA PCI is "hidden" until HDMI cable is plugged, then the > driver will flag the magic bit to make HDA audio appear on the PCI > bus. > IIRC the current approach is to make nouveau and device link work. But what happens if you plug the HDMI cable later and want to use the HDMI audio? It won't work with your fix, right? Takashi