diff options
Diffstat (limited to 'pci-Rework-ASPM-disable-code.patch')
| -rw-r--r-- | pci-Rework-ASPM-disable-code.patch | 287 |
1 files changed, 0 insertions, 287 deletions
diff --git a/pci-Rework-ASPM-disable-code.patch b/pci-Rework-ASPM-disable-code.patch deleted file mode 100644 index d6fb24320..000000000 --- a/pci-Rework-ASPM-disable-code.patch +++ /dev/null @@ -1,287 +0,0 @@ -Path: news.gmane.org!not-for-mail -From: Matthew Garrett <mjg@redhat.com> -Newsgroups: gmane.linux.acpi.devel,gmane.linux.kernel.pci,gmane.linux.kernel -Subject: [PATCH] pci: Rework ASPM disable code -Date: Thu, 10 Nov 2011 16:38:33 -0500 -Lines: 232 -Approved: news@gmane.org -Message-ID: <1320961113-5050-1-git-send-email-mjg@redhat.com> -NNTP-Posting-Host: lo.gmane.org -X-Trace: dough.gmane.org 1320961145 13112 80.91.229.12 (10 Nov 2011 21:39:05 GMT) -X-Complaints-To: usenet@dough.gmane.org -NNTP-Posting-Date: Thu, 10 Nov 2011 21:39:05 +0000 (UTC) -Cc: linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, - linux-kernel@vger.kernel.org, Matthew Garrett <mjg@redhat.com> -To: jbarnes@virtuousgeek.org -Original-X-From: linux-acpi-owner@vger.kernel.org Thu Nov 10 22:38:57 2011 -Return-path: <linux-acpi-owner@vger.kernel.org> -Envelope-to: glad-acpi-devel@lo.gmane.org -Original-Received: from vger.kernel.org ([209.132.180.67]) - by lo.gmane.org with esmtp (Exim 4.69) - (envelope-from <linux-acpi-owner@vger.kernel.org>) - id 1ROcKm-0003jN-CL - for glad-acpi-devel@lo.gmane.org; Thu, 10 Nov 2011 22:38:56 +0100 -Original-Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand - id S1751342Ab1KJViu (ORCPT <rfc822;glad-acpi-devel@m.gmane.org>); - Thu, 10 Nov 2011 16:38:50 -0500 -Original-Received: from mx1.redhat.com ([209.132.183.28]:32030 "EHLO mx1.redhat.com" - rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP - id S1750805Ab1KJVit (ORCPT <rfc822;linux-acpi@vger.kernel.org>); - Thu, 10 Nov 2011 16:38:49 -0500 -Original-Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) - by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id pAALcmdw013333 - (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); - Thu, 10 Nov 2011 16:38:49 -0500 -Original-Received: from cavan.codon.org.uk (ovpn-113-157.phx2.redhat.com [10.3.113.157]) - by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id pAALclkW022022 - (version=TLSv1/SSLv3 cipher=AES256-SHA bits=256 verify=NO); - Thu, 10 Nov 2011 16:38:48 -0500 -Original-Received: from 209-6-41-104.c3-0.smr-ubr1.sbo-smr.ma.cable.rcn.com ([209.6.41.104] helo=localhost.localdomain) - by cavan.codon.org.uk with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) - (Exim 4.72) - (envelope-from <mjg@redhat.com>) - id 1ROcKa-0000F4-E4; Thu, 10 Nov 2011 21:38:44 +0000 -X-SA-Do-Not-Run: Yes -X-SA-Exim-Connect-IP: 209.6.41.104 -X-SA-Exim-Mail-From: mjg@redhat.com -X-SA-Exim-Scanned: No (on cavan.codon.org.uk); SAEximRunCond expanded to false -X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 -Original-Sender: linux-acpi-owner@vger.kernel.org -Precedence: bulk -List-ID: <linux-acpi.vger.kernel.org> -X-Mailing-List: linux-acpi@vger.kernel.org -Xref: news.gmane.org gmane.linux.acpi.devel:51182 gmane.linux.kernel.pci:12503 gmane.linux.kernel:1214427 -Archived-At: <http://permalink.gmane.org/gmane.linux.acpi.devel/51182> - -Right now we forcibly clear ASPM state on all devices if the BIOS indicates -that the feature isn't supported. Based on the Microsoft presentation -"PCI Express In Depth for Windows Vista and Beyond", I'm starting to think -that this may be an error. The implication is that unless the platform -grants full control via _OSC, Windows will not touch any PCIe features - -including ASPM. In that case clearing ASPM state would be an error unless -the platform has granted us that control. - -This patch reworks the ASPM disabling code such that the actual clearing -of state is triggered by a successful handoff of PCIe control to the OS. -The general ASPM code undergoes some changes in order to ensure that the -ability to clear the bits isn't overridden by ASPM having already been -disabled. Further, this theoretically now allows for situations where -only a subset of PCIe roots hand over control, leaving the others in the -BIOS state. - -It's difficult to know for sure that this is the right thing to do - -there's zero public documentation on the interaction between all of these -components. But enough vendors enable ASPM on platforms and then set this -bit that it seems likely that they're expecting the OS to leave them alone. - -Measured to save around 5W on an idle Thinkpad X220. - -Signed-off-by: Matthew Garrett <mjg@redhat.com> ---- - drivers/acpi/pci_root.c | 7 +++++ - drivers/pci/pci-acpi.c | 1 - - drivers/pci/pcie/aspm.c | 58 +++++++++++++++++++++++++++++---------------- - include/linux/pci-aspm.h | 4 +- - 4 files changed, 46 insertions(+), 24 deletions(-) - -diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c -index 2672c79..7aff631 100644 ---- a/drivers/acpi/pci_root.c -+++ b/drivers/acpi/pci_root.c -@@ -596,6 +596,13 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device) - if (ACPI_SUCCESS(status)) { - dev_info(root->bus->bridge, - "ACPI _OSC control (0x%02x) granted\n", flags); -+ if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) { -+ /* -+ * We have ASPM control, but the FADT indicates -+ * that it's unsupported. Clear it. -+ */ -+ pcie_clear_aspm(root->bus); -+ } - } else { - dev_info(root->bus->bridge, - "ACPI _OSC request failed (%s), " -diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c -index 4ecb640..c8e7585 100644 ---- a/drivers/pci/pci-acpi.c -+++ b/drivers/pci/pci-acpi.c -@@ -395,7 +395,6 @@ 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_clear_aspm(); - pcie_no_aspm(); - } - -diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c -index cbfbab1..1cfbf22 100644 ---- a/drivers/pci/pcie/aspm.c -+++ b/drivers/pci/pcie/aspm.c -@@ -68,7 +68,7 @@ struct pcie_link_state { - struct aspm_latency acceptable[8]; - }; - --static int aspm_disabled, aspm_force, aspm_clear_state; -+static int aspm_disabled, aspm_force; - static bool aspm_support_enabled = true; - static DEFINE_MUTEX(aspm_lock); - static LIST_HEAD(link_list); -@@ -500,9 +500,6 @@ static int pcie_aspm_sanity_check(struct pci_dev *pdev) - int pos; - u32 reg32; - -- if (aspm_clear_state) -- return -EINVAL; -- - /* - * Some functions in a slot might not all be PCIe functions, - * very strange. Disable ASPM for the whole slot -@@ -574,9 +571,6 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev) - pdev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM) - return; - -- if (aspm_disabled && !aspm_clear_state) -- return; -- - /* VIA has a strange chipset, root port is under a bridge */ - if (pdev->pcie_type == PCI_EXP_TYPE_ROOT_PORT && - pdev->bus->self) -@@ -608,7 +602,7 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev) - * the BIOS's expectation, we'll do so once pci_enable_device() is - * called. - */ -- if (aspm_policy != POLICY_POWERSAVE || aspm_clear_state) { -+ if (aspm_policy != POLICY_POWERSAVE) { - pcie_config_aspm_path(link); - pcie_set_clkpm(link, policy_to_clkpm_state(link)); - } -@@ -649,8 +643,7 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev) - struct pci_dev *parent = pdev->bus->self; - struct pcie_link_state *link, *root, *parent_link; - -- if ((aspm_disabled && !aspm_clear_state) || !pci_is_pcie(pdev) || -- !parent || !parent->link_state) -+ if (!pci_is_pcie(pdev) || !parent || !parent->link_state) - return; - if ((parent->pcie_type != PCI_EXP_TYPE_ROOT_PORT) && - (parent->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)) -@@ -734,13 +727,18 @@ void pcie_aspm_powersave_config_link(struct pci_dev *pdev) - * pci_disable_link_state - disable pci device's link state, so the link will - * never enter specific states - */ --static void __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem) -+static void __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem, -+ bool force) - { - struct pci_dev *parent = pdev->bus->self; - struct pcie_link_state *link; - -- if (aspm_disabled || !pci_is_pcie(pdev)) -+ if (aspm_disabled && !force) -+ return; -+ -+ if (!pci_is_pcie(pdev)) - return; -+ - if (pdev->pcie_type == PCI_EXP_TYPE_ROOT_PORT || - pdev->pcie_type == PCI_EXP_TYPE_DOWNSTREAM) - parent = pdev; -@@ -768,16 +766,31 @@ static void __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem) - - void pci_disable_link_state_locked(struct pci_dev *pdev, int state) - { -- __pci_disable_link_state(pdev, state, false); -+ __pci_disable_link_state(pdev, state, false, false); - } - EXPORT_SYMBOL(pci_disable_link_state_locked); - - void pci_disable_link_state(struct pci_dev *pdev, int state) - { -- __pci_disable_link_state(pdev, state, true); -+ __pci_disable_link_state(pdev, state, true, false); - } - EXPORT_SYMBOL(pci_disable_link_state); - -+void pcie_clear_aspm(struct pci_bus *bus) -+{ -+ struct pci_dev *child; -+ -+ /* -+ * Clear any ASPM setup that the firmware has carried out on this bus -+ */ -+ list_for_each_entry(child, &bus->devices, bus_list) { -+ __pci_disable_link_state(child, PCIE_LINK_STATE_L0S | -+ PCIE_LINK_STATE_L1 | -+ PCIE_LINK_STATE_CLKPM, -+ false, true); -+ } -+} -+ - static int pcie_aspm_set_policy(const char *val, struct kernel_param *kp) - { - int i; -@@ -935,6 +948,7 @@ void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev) - static int __init pcie_aspm_disable(char *str) - { - if (!strcmp(str, "off")) { -+ aspm_policy = POLICY_DEFAULT; - aspm_disabled = 1; - aspm_support_enabled = false; - printk(KERN_INFO "PCIe ASPM is disabled\n"); -@@ -947,16 +961,18 @@ static int __init pcie_aspm_disable(char *str) - - __setup("pcie_aspm=", pcie_aspm_disable); - --void pcie_clear_aspm(void) --{ -- if (!aspm_force) -- aspm_clear_state = 1; --} -- - void pcie_no_aspm(void) - { -- if (!aspm_force) -+ /* -+ * Disabling ASPM is intended to prevent the kernel from modifying -+ * existing hardware state, not to clear existing state. To that end: -+ * (a) set policy to POLICY_DEFAULT in order to avoid changing state -+ * (b) prevent userspace from changing policy -+ */ -+ if (!aspm_force) { -+ aspm_policy = POLICY_DEFAULT; - aspm_disabled = 1; -+ } - } - - /** -diff --git a/include/linux/pci-aspm.h b/include/linux/pci-aspm.h -index 7cea7b6..c832014 100644 ---- a/include/linux/pci-aspm.h -+++ b/include/linux/pci-aspm.h -@@ -29,7 +29,7 @@ extern void pcie_aspm_pm_state_change(struct pci_dev *pdev); - extern void pcie_aspm_powersave_config_link(struct pci_dev *pdev); - extern void pci_disable_link_state(struct pci_dev *pdev, int state); - extern void pci_disable_link_state_locked(struct pci_dev *pdev, int state); --extern void pcie_clear_aspm(void); -+extern void pcie_clear_aspm(struct pci_bus *bus); - extern void pcie_no_aspm(void); - #else - static inline void pcie_aspm_init_link_state(struct pci_dev *pdev) -@@ -47,7 +47,7 @@ static inline void pcie_aspm_powersave_config_link(struct pci_dev *pdev) - static inline void pci_disable_link_state(struct pci_dev *pdev, int state) - { - } --static inline void pcie_clear_aspm(void) -+static inline void pcie_clear_aspm(struct pci_bus *bus) - { - } - static inline void pcie_no_aspm(void) --- -1.7.7.1 - --- -To unsubscribe from this list: send the line "unsubscribe linux-acpi" in -the body of a message to majordomo@vger.kernel.org -More majordomo info at http://vger.kernel.org/majordomo-info.html - |