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| author | Johan Hovold <johan+linaro@kernel.org> | 2023-11-28 09:15:08 +0100 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2023-12-11 19:07:59 +0100 |
| commit | 49de0dc87965079a8e2803ee4b39f9d946259423 (patch) | |
| tree | e98ddb337f14976156eba96d36063965a5da6d32 | |
| parent | PCI/ASPM: Add pci_enable_link_state_locked() (diff) | |
| download | linux-49de0dc87965079a8e2803ee4b39f9d946259423.tar.xz linux-49de0dc87965079a8e2803ee4b39f9d946259423.zip | |
PCI: vmd: Fix potential deadlock when enabling ASPM
The vmd_pm_enable_quirk() helper is called from pci_walk_bus() during
probe to enable ASPM for controllers with VMD_FEAT_BIOS_PM_QUIRK set.
Since pci_walk_bus() already holds a pci_bus_sem read lock, use
pci_enable_link_state_locked() to enable link states in order to avoid a
potential deadlock (e.g. in case someone takes a write lock before
reacquiring the read lock).
Fixes: f492edb40b54 ("PCI: vmd: Add quirk to configure PCIe ASPM and LTR")
Link: https://lore.kernel.org/r/20231128081512.19387-3-johan+linaro@kernel.org
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
[bhelgaas: add "potential" in subject since the deadlock has only been
reported by lockdep, include helper name in commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: <stable@vger.kernel.org> # 6.3
Cc: Michael Bottini <michael.a.bottini@linux.intel.com>
Cc: David E. Box <david.e.box@linux.intel.com>
| -rw-r--r-- | drivers/pci/controller/vmd.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index 94ba61fe1c44..0452cbc362ee 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -751,7 +751,7 @@ static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata) if (!(features & VMD_FEAT_BIOS_PM_QUIRK)) return 0; - pci_enable_link_state(pdev, PCIE_LINK_STATE_ALL); + pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL); pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_LTR); if (!pos) |