From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752538Ab3GIKKo (ORCPT ); Tue, 9 Jul 2013 06:10:44 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:35433 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751015Ab3GIKKn (ORCPT ); Tue, 9 Jul 2013 06:10:43 -0400 Date: Tue, 9 Jul 2013 12:10:39 +0200 From: Pavel Machek To: Greg KH Cc: kernel list , joe.lawrence@stratus.com, myron.stowe@redhat.com, bhelgaas@google.com Subject: Re: /sys/module/pcie_aspm/parameters/policy not writable? Message-ID: <20130709101039.GA4479@amd.pavel.ucw.cz> References: <20130709012611.GA22371@amd.pavel.ucw.cz> <20130709041321.GA30555@kroah.com> <20130709094906.GA3870@amd.pavel.ucw.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130709094906.GA3870@amd.pavel.ucw.cz> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! > > > My thinkpad has rather high ping latencies... and perhaps it is due to > > > PCIE ASPM. > > > > Why would that be the problem? The odds that the PCIE bus is the issue > > seems strange to me. > > Aha: I guess that's why the file is not writable: > > pavel@amd:~$ dmesg | grep -i aspm > ACPI FADT declares the system doesn't support PCIe ASPM, so disable it > e1000e 0000:02:00.0: Disabling ASPM L0s L1 > pavel@amd:~$ cat /sys/module/pcie_aspm/parameters/policy > [default] performance powersave > pavel@amd:~$ > root@amd:~# echo -n performance > > /sys/module/pcie_aspm/parameters/policy > -su: echo: write error: Operation not permitted > root@amd:~# > > But: > 1) it should not list unavailable options > > 2) operation not permitted seems like wrong error code for > operation not supported. So I forcibly enabled ASPM, and now ping latencies are in normal range... no matter how I set /sys/module/pcie_aspm/parameters/policy. Strange. Any ideas what correct solution is? Pavel Signed-off-by: Pavel Machek (but don't apply) diff --git a/.config b/.config index 149f713..d7f5a11 100644 --- a/.config +++ b/.config @@ -1,6 +1,6 @@ # # Automatically generated file; DO NOT EDIT. -# Linux/x86 3.10.0-rc2 Kernel Configuration +# Linux/x86 3.10.0 Kernel Configuration # # CONFIG_64BIT is not set CONFIG_X86_32=y @@ -559,9 +559,9 @@ CONFIG_PCIEAER=y # CONFIG_PCIEAER_INJECT is not set CONFIG_PCIEASPM=y CONFIG_PCIEASPM_DEBUG=y -CONFIG_PCIEASPM_DEFAULT=y +# CONFIG_PCIEASPM_DEFAULT is not set # CONFIG_PCIEASPM_POWERSAVE is not set -# CONFIG_PCIEASPM_PERFORMANCE is not set +CONFIG_PCIEASPM_PERFORMANCE=y CONFIG_PCIE_PME=y CONFIG_ARCH_SUPPORTS_MSI=y # CONFIG_PCI_MSI is not set @@ -1340,7 +1340,10 @@ CONFIG_MD_RAID1=y # CONFIG_MD_RAID456 is not set # CONFIG_MD_MULTIPATH is not set # CONFIG_MD_FAULTY is not set -# CONFIG_BCACHE is not set +CONFIG_BCACHE=y +# CONFIG_BCACHE_DEBUG is not set +# CONFIG_BCACHE_EDEBUG is not set +# CONFIG_BCACHE_CLOSURES_DEBUG is not set CONFIG_BLK_DEV_DM=y # CONFIG_DM_DEBUG is not set CONFIG_DM_CRYPT=y diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index e4b1fb2..9a1b63e 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -382,7 +382,7 @@ static int __init acpi_pci_init(void) if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) { printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n"); - pcie_no_aspm(); +// pcie_no_aspm(); } ret = register_acpi_bus_type(&acpi_pci_bus); -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html