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authorKai-Heng Feng <kai.heng.feng@canonical.com>2020-05-06 01:34:21 +0800
committerBjorn Helgaas <bhelgaas@google.com>2020-05-07 16:39:44 -0500
commit66ff14e59e8a30690755b08bc3042359703fb07a (patch)
treec8cdf508573002279c8a5406e0eb2b02665d7c0f /drivers/pci/pcie
parent8f3d9f354286745c751374f5f1fcafee6b3f3136 (diff)
downloadlinux-66ff14e59e8a30690755b08bc3042359703fb07a.tar.bz2
PCI/ASPM: Allow ASPM on links to PCIe-to-PCI/PCI-X Bridges
7d715a6c1ae5 ("PCI: add PCI Express ASPM support") added the ability for Linux to enable ASPM, but for some undocumented reason, it didn't enable ASPM on links where the downstream component is a PCIe-to-PCI/PCI-X Bridge. Remove this exclusion so we can enable ASPM on these links. The Dell OptiPlex 7080 mentioned in the bugzilla has a TI XIO2001 PCIe-to-PCI Bridge. Enabling ASPM on the link leading to it allows the Intel SoC to enter deeper Package C-states, which is a significant power savings. [bhelgaas: commit log] Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=207571 Link: https://lore.kernel.org/r/20200505173423.26968-1-kai.heng.feng@canonical.com Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Diffstat (limited to 'drivers/pci/pcie')
-rw-r--r--drivers/pci/pcie/aspm.c10
1 files changed, 0 insertions, 10 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 2378ed692534..b17e5ffd31b1 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -628,16 +628,6 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
/* Setup initial capable state. Will be updated later */
link->aspm_capable = link->aspm_support;
- /*
- * If the downstream component has pci bridge function, don't
- * do ASPM for now.
- */
- list_for_each_entry(child, &linkbus->devices, bus_list) {
- if (pci_pcie_type(child) == PCI_EXP_TYPE_PCI_BRIDGE) {
- link->aspm_disable = ASPM_STATE_ALL;
- break;
- }
- }
/* Get and check endpoint acceptable latencies */
list_for_each_entry(child, &linkbus->devices, bus_list) {