From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Vegard Nossum" Subject: Re: [PATCH] ACPI: don't walk tables if ACPI was disabled Date: Fri, 20 Jun 2008 23:27:25 +0200 Message-ID: <19f34abd0806201427h740ca3e7gc2f01c7e34616fd4@mail.gmail.com> References: <20080620135639.GA5073@damson.getinternet.no> <19f34abd0806201340t502ce471n578dd2498a5f1992@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from yw-out-2324.google.com ([74.125.46.29]:6124 "EHLO yw-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754566AbYFTV11 (ORCPT ); Fri, 20 Jun 2008 17:27:27 -0400 Received: by yw-out-2324.google.com with SMTP id 9so840080ywe.1 for ; Fri, 20 Jun 2008 14:27:25 -0700 (PDT) In-Reply-To: <19f34abd0806201340t502ce471n578dd2498a5f1992@mail.gmail.com> Content-Disposition: inline Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Len Brown Cc: Ingo Molnar , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, Zhao Yakui , "Rafael J. Wysocki" , Alexey Starikovskiy , Yinghai Lu , Bjorn Helgaas On Fri, Jun 20, 2008 at 10:40 PM, Vegard Nossum wrote: > On Fri, Jun 20, 2008 at 9:00 PM, Len Brown wrote: >>> @@ -333,6 +333,9 @@ static int __init acpi_rtc_init(void) >>> { >>> struct device *dev = get_rtc_dev(); >>> >>> + if (acpi_disabled) >>> + return 0; >>> + >> >> hmm, i would expect dev to be 0 for acpi=off, >> since pnp_match would fail, no? > > Obviously not. Because Ingo is booting with acpi=off and he still gets > a warning about some mutex operation that originates from this very > initcall: > > [ 3.976213] calling acpi_rtc_init+0x0/0xd3 > [ 3.980213] ACPI Exception (utmutex-0263): AE_BAD_PARAMETER, Thread > F7C50000 could not acquire Mutex [3] [20080321] > > Aha. The device in question (PNP0b00) is discovered while doing pnpbios_init(), NOT pnpacpi_init: [ 1.712032] initcall pnpacpi_init+0x0/0x80 returned 0 after 3 msecs [ 1.716032] calling pnpbios_init+0x0/0x322 [ 1.720032] PnPBIOS: Scanning system for PnP BIOS support... [ 1.724032] PnPBIOS: Found PnP BIOS installation structure at 0xc00fc550 [ 1.728032] PnPBIOS: PnP BIOS version 1.0, entry 0xf0000:0xc580, dseg 0xf0000 ... [ 1.876032] pnp 00:03: parse allocated resources [ 1.880032] pnp 00:03: add irq 8 flags 0x0 [ 1.884032] pnp 00:03: add io 0x70-0x71 flags 0x0 [ 1.888032] pnp 00:03: parse resource options [ 1.892032] pnp 00:03: new independent option [ 1.896032] device: '00:03': device_add [ 1.900032] bus: 'pnp': add device 00:03 [ 1.904032] PM: Adding info for pnp:00:03 [ 1.908032] pnp 00:03: Plug and Play BIOS device, IDs PNP0b00 (active) So I guess this function, pnpbios_init() needs the check as well. In fact, it has this: #ifdef CONFIG_PNPACPI if (!acpi_disabled && !pnpacpi_disabled) { pnpbios_disabled = 1; printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n"); return -ENODEV; } #endif /* CONFIG_ACPI */ ...I guess that should be changed to say if (acpi_disabled || pnpacpi_disabled)? Or... I don't understand the purpose of the original test. But it seems to be there since the beginning of time (or, well, v2.6.12-rc2). Vegard -- "The animistic metaphor of the bug that maliciously sneaked in while the programmer was not looking is intellectually dishonest as it disguises that the error is the programmer's own creation." -- E. W. Dijkstra, EWD1036