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PCI/DPC: Disable DPC service on suspend

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If the link is powered off during suspend, electrical noise may cause
errors that trigger DPC.  If the DPC interrupt is enabled and shares an IRQ
with PME, that causes a spurious wakeup during suspend.

Disable DPC triggering and the DPC interrupt during suspend to prevent
this.  Clear DPC interrupt status before re-enabling DPC interrupts during
resume so we don't get an interrupt for errors that occurred during the
suspend/resume process.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=209149
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216295
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218090
Link: https://lore.kernel.org/r/20240416043225.1462548-3-kai.heng.feng@canonical.com
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
[bhelgaas: clear status on resume, add comments, commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Kai-Heng Feng 2024-04-16 12:32:25 +08:00 committed by Bjorn Helgaas
parent 5afc2f763e
commit 75c47c790f
1 changed files with 48 additions and 12 deletions
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60
drivers/pci/pcie/dpc.c
View File

@ -412,13 +412,44 @@ void pci_dpc_init(struct pci_dev *pdev)
}
}
static void dpc_enable(struct pcie_device *dev)
{
struct pci_dev *pdev = dev->port;
int dpc = pdev->dpc_cap;
u16 ctl;
/*
* Clear DPC Interrupt Status so we don't get an interrupt for an
* old event when setting DPC Interrupt Enable.
*/
pci_write_config_word(pdev, dpc + PCI_EXP_DPC_STATUS,
PCI_EXP_DPC_STATUS_INTERRUPT);
pci_read_config_word(pdev, dpc + PCI_EXP_DPC_CTL, &ctl);
ctl &= ~PCI_EXP_DPC_CTL_EN_MASK;
ctl |= PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN;
pci_write_config_word(pdev, dpc + PCI_EXP_DPC_CTL, ctl);
}
static void dpc_disable(struct pcie_device *dev)
{
struct pci_dev *pdev = dev->port;
int dpc = pdev->dpc_cap;
u16 ctl;
/* Disable DPC triggering and DPC interrupts */
pci_read_config_word(pdev, dpc + PCI_EXP_DPC_CTL, &ctl);
ctl &= ~(PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN);
pci_write_config_word(pdev, dpc + PCI_EXP_DPC_CTL, ctl);
}
#define FLAG(x, y) (((x) & (y)) ? '+' : '-')
static int dpc_probe(struct pcie_device *dev)
{
struct pci_dev *pdev = dev->port;
struct device *device = &dev->device;
int status;
u16 ctl, cap;
u16 cap;
if (!pcie_aer_is_native(pdev) && !pcie_ports_dpc_native)
return -ENOTSUPP;
@ -433,11 +464,7 @@ static int dpc_probe(struct pcie_device *dev)
}
pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CAP, &cap);
pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, &ctl);
ctl &= ~PCI_EXP_DPC_CTL_EN_MASK;
ctl |= PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN;
pci_write_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, ctl);
dpc_enable(dev);
pci_info(pdev, "enabled with IRQ %d\n", dev->irq);
pci_info(pdev, "error containment capabilities: Int Msg #%d, RPExt%c PoisonedTLP%c SwTrigger%c RP PIO Log %d, DL_ActiveErr%c\n",
@ -450,14 +477,21 @@ static int dpc_probe(struct pcie_device *dev)
return status;
}
static int dpc_suspend(struct pcie_device *dev)
{
dpc_disable(dev);
return 0;
}
static int dpc_resume(struct pcie_device *dev)
{
dpc_enable(dev);
return 0;
}
static void dpc_remove(struct pcie_device *dev)
{
struct pci_dev *pdev = dev->port;
u16 ctl;
pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, &ctl);
ctl &= ~(PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN);
pci_write_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, ctl);
dpc_disable(dev);
}
static struct pcie_port_service_driver dpcdriver = {
@ -465,6 +499,8 @@ static struct pcie_port_service_driver dpcdriver = {
.port_type = PCIE_ANY_PORT,
.service = PCIE_PORT_SERVICE_DPC,
.probe = dpc_probe,
.suspend = dpc_suspend,
.resume = dpc_resume,
.remove = dpc_remove,
};