lkml.org 
[lkml]   [2020]   [Jun]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.7 174/477] PCI/ASPM: Allow ASPM on links to PCIe-to-PCI/PCI-X Bridges
    Date
    From: Kai-Heng Feng <kai.heng.feng@canonical.com>

    [ Upstream commit 66ff14e59e8a30690755b08bc3042359703fb07a ]

    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>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/pci/pcie/aspm.c | 10 ----------
    1 file changed, 10 deletions(-)

    diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
    index 2378ed6925346..b17e5ffd31b14 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) {
    --
    2.25.1


    \
     
     \ /
      Last update: 2020-06-23 23:39    [W:4.087 / U:0.192 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site