On Thu, Mar 30, 2023 at 05:41:35PM +0530, Swati Sharma wrote: > From: "David E. Box" <david.e.box@xxxxxxxxxxxxxxx> > > The VMD driver calls pci_enabled_link_state as a callback from > pci_bus_walk. Both will acquire the pci_bus_sem lock leading to a lockdep > warning. Add an argument to pci_enable_link_state to set whether the lock > should be acquired. In the VMD driver, set the argument to false since the > lock will already be obtained by pci_bus_walk. > > Still, review comments needs to be addressed. However, this fix > is helping to unblock CI execution for now. > > References: https://gitlab.freedesktop.org/drm/intel/-/issues/8316 > Reported-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > Fixes: de82f60f9c86 ("PCI/ASPM: Add pci_enable_link_state()") > Link: https://lore.kernel.org/linux-pci/ZBjko%2FifunIwsK2v@xxxxxxxxx/ > Signed-off-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx> > Signed-off-by: Swati Sharma <swati2.sharma@xxxxxxxxx> Acked-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> to get this into topic/core-for-CI > --- > drivers/pci/controller/vmd.c | 2 +- > drivers/pci/pcie/aspm.c | 9 ++++++--- > include/linux/pci.h | 5 +++-- > 3 files changed, 10 insertions(+), 6 deletions(-) > > diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c > index 990630ec57c6..45aa35744eae 100644 > --- a/drivers/pci/controller/vmd.c > +++ b/drivers/pci/controller/vmd.c > @@ -737,7 +737,7 @@ 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(pdev, PCIE_LINK_STATE_ALL, false); > > pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_LTR); > if (!pos) > diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c > index 66d7514ca111..5b5a600bb864 100644 > --- a/drivers/pci/pcie/aspm.c > +++ b/drivers/pci/pcie/aspm.c > @@ -1147,8 +1147,9 @@ EXPORT_SYMBOL(pci_disable_link_state); > * > * @pdev: PCI device > * @state: Mask of ASPM link states to enable > + * @sem: Boolean to acquire/release pci_bus_sem > */ > -int pci_enable_link_state(struct pci_dev *pdev, int state) > +int pci_enable_link_state(struct pci_dev *pdev, int state, bool sem) > { > struct pcie_link_state *link = pcie_aspm_get_link(pdev); > > @@ -1165,7 +1166,8 @@ int pci_enable_link_state(struct pci_dev *pdev, int state) > return -EPERM; > } > > - down_read(&pci_bus_sem); > + if (sem) > + down_read(&pci_bus_sem); > mutex_lock(&aspm_lock); > link->aspm_default = 0; > if (state & PCIE_LINK_STATE_L0S) > @@ -1186,7 +1188,8 @@ int pci_enable_link_state(struct pci_dev *pdev, int state) > link->clkpm_default = (state & PCIE_LINK_STATE_CLKPM) ? 1 : 0; > pcie_set_clkpm(link, policy_to_clkpm_state(link)); > mutex_unlock(&aspm_lock); > - up_read(&pci_bus_sem); > + if (sem) > + up_read(&pci_bus_sem); > > return 0; > } > diff --git a/include/linux/pci.h b/include/linux/pci.h > index b50e5c79f7e3..1fe4557e87b9 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1708,7 +1708,7 @@ extern bool pcie_ports_native; > #ifdef CONFIG_PCIEASPM > int pci_disable_link_state(struct pci_dev *pdev, int state); > int pci_disable_link_state_locked(struct pci_dev *pdev, int state); > -int pci_enable_link_state(struct pci_dev *pdev, int state); > +int pci_enable_link_state(struct pci_dev *pdev, int state, bool sem); > void pcie_no_aspm(void); > bool pcie_aspm_support_enabled(void); > bool pcie_aspm_enabled(struct pci_dev *pdev); > @@ -1717,7 +1717,8 @@ static inline int pci_disable_link_state(struct pci_dev *pdev, int state) > { return 0; } > static inline int pci_disable_link_state_locked(struct pci_dev *pdev, int state) > { return 0; } > -static inline int pci_enable_link_state(struct pci_dev *pdev, int state) > +static inline int > +pci_enable_link_state(struct pci_dev *pdev, int state, bool sem) > { return 0; } > static inline void pcie_no_aspm(void) { } > static inline bool pcie_aspm_support_enabled(void) { return false; } > -- > 2.25.1 >
