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| author | Bjorn Helgaas <bhelgaas@google.com> | 2022-09-09 15:25:00 -0500 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2022-09-12 15:29:37 -0500 |
| commit | e8bdc5ea481638e0a4fd5639050d2b170417f493 (patch) | |
| tree | 84ad8da885d4b5aad8def5c1c52f38811fedb77e /include | |
| parent | 118b9dfdc18b68abf736a71330e3ad1f5af7e47e (diff) | |
| download | linux-stable-e8bdc5ea481638e0a4fd5639050d2b170417f493.tar.gz linux-stable-e8bdc5ea481638e0a4fd5639050d2b170417f493.tar.bz2 linux-stable-e8bdc5ea481638e0a4fd5639050d2b170417f493.zip | |
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 'include')
| -rw-r--r-- | include/linux/pci.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/pci.h b/include/linux/pci.h index 54be939023a3..cb5f796e3319 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1678,10 +1678,12 @@ bool pci_ats_disabled(void); #ifdef CONFIG_PCIE_PTM int pci_enable_ptm(struct pci_dev *dev, u8 *granularity); +void pci_disable_ptm(struct pci_dev *dev); bool pcie_ptm_enabled(struct pci_dev *dev); #else static inline int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) { return -EINVAL; } +static inline void pci_disable_ptm(struct pci_dev *dev) { } static inline bool pcie_ptm_enabled(struct pci_dev *dev) { return false; } #endif |