Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755861Ab2BGQyc (ORCPT ); Tue, 7 Feb 2012 11:54:32 -0500 Received: from enyo.dsw2k3.info ([195.71.86.239]:57114 "EHLO enyo.dsw2k3.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751507Ab2BGQya (ORCPT ); Tue, 7 Feb 2012 11:54:30 -0500 Date: Tue, 7 Feb 2012 17:54:16 +0100 From: Matthias Schniedermeyer To: Linus Torvalds Cc: Clemens Ladisch , Matthew Garrett , Greg KH , linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: Linux 3.2.5 Message-ID: <20120207165416.GA27342@citd.de> References: <20120206181622.GA28811@kroah.com> <20120207084037.GA6140@citd.de> <4F30FABF.4060409@ladisch.de> <20120207105835.GA12864@citd.de> <4F310DBC.1040501@ladisch.de> <20120207114806.GA15323@citd.de> <4F3118F7.8050205@ladisch.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3875 Lines: 99 On 07.02.2012 08:29, Linus Torvalds wrote: > [ Matthew wasn't cc'd for this thread - see lkml or ask me or Greg to > forward you the relevant emails ] > > On Tue, Feb 7, 2012 at 4:28 AM, Clemens Ladisch wrote: > > > > According to your logs, 3.2.4 didn't touch device 5:0, while 3.2.5 does > > disable ASPM. ?(Are there any other messages regarding 0000:05:00.0?) > > Actually, if I read things right, I think 3.2.4 did touch the device > too, just without the message. > > One of the things that the aspm patch does is to remove the code that used to do > > - if (aspm_clear_state) > - return -EINVAL; > > in pcie_aspm_sanity_check(). So what I think happened for Matthias in > 3.2.4 is that "pcie_aspm_sanity_check()" *always* failed (silently). > Which caused us to disable ASPM for *every* device, and not even talk > about it. > > With the new patch in place, 3.2.5 gets past that check, and > pcie_aspm_sanity_check() now fails (with the message) for *some* > devices. Which then causes us to disable ASPM for *those* devices, but > not others. And that just sounds insane. It's sounds very broken for > this situation, because the BIOS had apparently enabled ASPM for the > PCIe bridge and the soubdblaster device, but then the "sanity check" > disabled ASPM for the bridge (and presumably left it on for the > soubdblaster). > > Resulting in a broken system - aspm on the device, but not the bridge > leading up to it. Which I do not think is a correct situation. > > So aspm=force fixes the issue because it forces aspm for everything - > which is fine. And 3.2.4 worked, because it *cleared* aspm for > everything. But 3.2.5 (and presumably current -git) does not work, > presumably because it clears ASPM randomly for bridge devices, while > leaving it on for the devices they bridge to. > > Quite frankly, I think the pcie_aspm_sanity_check() logic is > fundamentally broken. It's broken because it violates the whole point > of the new model: it touches ASPM state for devices that firmware has > set up, and it shouldn't touch it for! > > (It's also broken because it fundamentally makes the aspm disable be > "per device", which seems totally wrong - aspm is a system issue, you > can't just willy-nilly randomly enable it for one device without > taking other devices into account). > > So I suspect the whole pcie_aspm_sanity_check() function should go away. > > Matthias - can you try to trivially just make pcie_aspm_sanity_check() > always return 0 - remove the contents of that function, and just > replace them all with just a simple "return 0;". Does that make things > work for you? So 3.2.5 with the following patch and without pcie_aspm=force: - snip - --- drivers/pci/pcie/aspm.c.orig 2012-02-07 15:17:05.068401852 +0100 +++ drivers/pci/pcie/aspm.c 2012-02-07 17:47:27.304684977 +0100 @@ -500,6 +500,8 @@ int pos; u32 reg32; + return 0; + /* * Some functions in a slot might not all be PCIe functions, * very strange. Disable ASPM for the whole slot - snip - Sound works. :-) dmesg | grep -i aspm [ 0.762726] ACPI FADT declares the system doesn't support PCIe ASPM, so disable it [ 0.792913] ACPI _OSC control for PCIe not granted, disabling ASPM [ 1.627719] e1000e 0000:03:00.0: Disabling ASPM L1 Bis denn -- Real Programmers consider "what you see is what you get" to be just as bad a concept in Text Editors as it is in women. No, the Real Programmer wants a "you asked for it, you got it" text editor -- complicated, cryptic, powerful, unforgiving, dangerous. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/