| Message ID | 20220902233543.390890-2-helgaas@kernel.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | PCI/PM: Always disable PTM for all devices during suspend | expand |
Hi, On 9/2/22 4:35 PM, Bjorn Helgaas wrote: > From: Bjorn Helgaas <bhelgaas@google.com> > > When disabling PTM, there's no need to clear the Root Select bit. We > disable PTM during suspend, and we want to re-enable it during resume. > Clearing Root Select here makes re-enabling more complicated. > > Per PCIe r6.0, sec 7.9.15.3, "When set, if the PTM Enable bit is also Set, > this Time Source is the PTM Root," so if PTM Enable is cleared, the value > of Root Select should be irrelevant. > > Preserve Root Select to simplify re-enabling PTM. > > Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> > Cc: David E. Box <david.e.box@linux.intel.com> > --- Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> > drivers/pci/pcie/ptm.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c > index 368a254e3124..b6a417247ce3 100644 > --- a/drivers/pci/pcie/ptm.c > +++ b/drivers/pci/pcie/ptm.c > @@ -42,7 +42,7 @@ void pci_disable_ptm(struct pci_dev *dev) > return; > > pci_read_config_word(dev, ptm + PCI_PTM_CTRL, &ctrl); > - ctrl &= ~(PCI_PTM_CTRL_ENABLE | PCI_PTM_CTRL_ROOT); > + ctrl &= ~PCI_PTM_CTRL_ENABLE; > pci_write_config_word(dev, ptm + PCI_PTM_CTRL, ctrl); > } >
diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c index 368a254e3124..b6a417247ce3 100644 --- a/drivers/pci/pcie/ptm.c +++ b/drivers/pci/pcie/ptm.c @@ -42,7 +42,7 @@ void pci_disable_ptm(struct pci_dev *dev) return; pci_read_config_word(dev, ptm + PCI_PTM_CTRL, &ctrl); - ctrl &= ~(PCI_PTM_CTRL_ENABLE | PCI_PTM_CTRL_ROOT); + ctrl &= ~PCI_PTM_CTRL_ENABLE; pci_write_config_word(dev, ptm + PCI_PTM_CTRL, ctrl); }