]> git.baikalelectronics.ru Git - kernel.git/commit
PCI/ASPM: Do not initialize link state when aspm_disabled is set
authorPatrick Talbert <ptalbert@redhat.com>
Wed, 5 Sep 2018 07:12:53 +0000 (09:12 +0200)
committerBjorn Helgaas <bhelgaas@google.com>
Tue, 18 Sep 2018 21:19:06 +0000 (16:19 -0500)
commit937b26e7db64d36edb7d8556f518d05daa81f97b
tree3bd784b7eee102e171b50b21e4e16dbe133ea6b3
parentef933b6c64efa82dc39ff45c8ce0d96e5f60f58f
PCI/ASPM: Do not initialize link state when aspm_disabled is set

Now that ASPM is configured for *all* PCIe devices at boot, a problem is
seen with systems that set the FADT NO_ASPM bit.  This bit indicates that
the OS should not alter the ASPM state, but when
pcie_aspm_init_link_state() runs it only checks for !aspm_support_enabled.
This misses the ACPI_FADT_NO_ASPM case because that is setting
aspm_disabled.

The result is systems may hang at boot after e452824; avoidable if they
boot with pcie_aspm=off (sets !aspm_support_enabled).

Fix this by having aspm_init_link_state() check for either
!aspm_support_enabled or acpm_disabled.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=201001
Fixes: e4528241211e ("PCI: Configure *all* devices, not just hot-added ones")
Signed-off-by: Patrick Talbert <ptalbert@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
drivers/pci/pcie/aspm.c