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authorBjorn Helgaas <bhelgaas@google.com>2022-09-09 23:25:00 +0300
committerBjorn Helgaas <bhelgaas@google.com>2022-09-12 23:29:37 +0300
commite8bdc5ea481638e0a4fd5639050d2b170417f493 (patch)
tree84ad8da885d4b5aad8def5c1c52f38811fedb77e /drivers/pci/pci.h
parent118b9dfdc18b68abf736a71330e3ad1f5af7e47e (diff)
downloadlinux-e8bdc5ea481638e0a4fd5639050d2b170417f493.tar.xz
PCI/PTM: Add pci_suspend_ptm() and pci_resume_ptm()
We disable PTM during suspend because that allows some Root Ports to enter lower-power PM states, which means we also need to disable PTM for all downstream devices. Add pci_suspend_ptm() and pci_resume_ptm() for this purpose. pci_enable_ptm() and pci_disable_ptm() are for drivers to use to enable or disable PTM. They use dev->ptm_enabled to keep track of whether PTM should be enabled. pci_suspend_ptm() and pci_resume_ptm() are PCI core-internal functions to temporarily disable PTM during suspend and (depending on dev->ptm_enabled) re-enable PTM during resume. Enable/disable/suspend/resume all use internal __pci_enable_ptm() and __pci_disable_ptm() functions that only update the PTM Control register. Outline: pci_enable_ptm(struct pci_dev *dev) { __pci_enable_ptm(dev); dev->ptm_enabled = 1; pci_ptm_info(dev); } pci_disable_ptm(struct pci_dev *dev) { if (dev->ptm_enabled) { __pci_disable_ptm(dev); dev->ptm_enabled = 0; } } pci_suspend_ptm(struct pci_dev *dev) { if (dev->ptm_enabled) __pci_disable_ptm(dev); } pci_resume_ptm(struct pci_dev *dev) { if (dev->ptm_enabled) __pci_enable_ptm(dev); } Nothing currently calls pci_resume_ptm(); the suspend path saves the PTM state before disabling PTM, so the PTM state restore in the resume path implicitly re-enables it. A future change will use pci_resume_ptm() to fix some problems with this approach. Link: https://lore.kernel.org/r/20220909202505.314195-5-helgaas@kernel.org Tested-by: Rajvi Jingar <rajvi.jingar@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Diffstat (limited to 'drivers/pci/pci.h')
-rw-r--r--drivers/pci/pci.h6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 785f31086313..ce4a277e3f41 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -507,11 +507,13 @@ static inline int pci_iov_bus_range(struct pci_bus *bus)
#ifdef CONFIG_PCIE_PTM
void pci_save_ptm_state(struct pci_dev *dev);
void pci_restore_ptm_state(struct pci_dev *dev);
-void pci_disable_ptm(struct pci_dev *dev);
+void pci_suspend_ptm(struct pci_dev *dev);
+void pci_resume_ptm(struct pci_dev *dev);
#else
static inline void pci_save_ptm_state(struct pci_dev *dev) { }
static inline void pci_restore_ptm_state(struct pci_dev *dev) { }
-static inline void pci_disable_ptm(struct pci_dev *dev) { }
+static inline void pci_suspend_ptm(struct pci_dev *dev) { }
+static inline void pci_resume_ptm(struct pci_dev *dev) { }
#endif
unsigned long pci_cardbus_resource_alignment(struct resource *);