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authorJohan Hovold <johan+linaro@kernel.org>2023-11-28 09:15:08 +0100
committerBjorn Helgaas <bhelgaas@google.com>2023-12-11 12:07:59 -0600
commit49de0dc87965079a8e2803ee4b39f9d946259423 (patch)
treee98ddb337f14976156eba96d36063965a5da6d32
parent718ab8226636a1a3a7d281f5d6a7ad7c925efe5a (diff)
downloadlinux-49de0dc87965079a8e2803ee4b39f9d946259423.tar.gz
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.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 94ba61fe1c4411..0452cbc362eef7 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)