In addition to nearest upstream bridge, driver may want to know if the
entire hierarchy can be powered off to perform different action.
So walk higher up the hierarchy to find out if any device has valid
_PR3.
The user will be introduced in next patch.
Signed-off-by: Kai-Heng Feng <[email protected]>
---
v8:
- No change.
drivers/pci/pci.c | 16 ++++++++++++++++
include/linux/pci.h | 2 ++
2 files changed, 18 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e5f243dd4288..7a5662f116b8 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -6225,6 +6225,22 @@ bool pci_pr3_present(struct pci_dev *pdev)
acpi_has_method(adev->handle, "_PR3");
}
EXPORT_SYMBOL_GPL(pci_pr3_present);
+
+bool pci_ancestor_pr3_present(struct pci_dev *pdev)
+{
+ struct pci_dev *parent = pdev;
+
+ if (acpi_disabled)
+ return false;
+
+ while ((parent = pci_upstream_bridge(parent))) {
+ if (pci_pr3_present(pdev))
+ return true;
+ }
+
+ return false;
+}
+EXPORT_SYMBOL_GPL(pci_ancestor_pr3_present);
#endif
/**
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 16493426a04f..cd71ebfd0f89 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -2620,10 +2620,12 @@ struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus);
void
pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *));
bool pci_pr3_present(struct pci_dev *pdev);
+bool pci_ancestor_pr3_present(struct pci_dev *pdev);
#else
static inline struct irq_domain *
pci_host_bridge_acpi_msi_domain(struct pci_bus *bus) { return NULL; }
static inline bool pci_pr3_present(struct pci_dev *pdev) { return false; }
+static inline bool pci_ancestor_pr3_present(struct pci_dev *pdev) { return false; }
#endif
#ifdef CONFIG_EEH
--
2.34.1
When the power rail gets cut off, the hardware can create some electric
noise on the link that triggers AER. If IRQ is shared between AER with
PME, such AER noise will cause a spurious wakeup on system suspend.
When the power rail gets back, the firmware of the device resets itself
and can create unexpected behavior like sending PTM messages. If DPC is
enabled, the DPC reset happens before driver's resume routine. The DPC
reset usually fails because the device is not in the right state, and
the resume also fails because the device is being reset by hardware. If
the scenario happens to device like NVMe, it means the whole system
resume fails.
As Per PCIe Base Spec 5.0, section 5.2, titled "Link State Power
Management", TLP and DLLP transmission are disabled for a Link in L2/L3
Ready (D3hot), L2 (D3cold with aux power) and L3 (D3cold) states. So if
the power will be turned off during suspend process, disable DPC service
and re-enable it during the resume process. This should not affect the
basic functionality.
Furthermore, since DPC depends on AER to function, and AER is disabled
in previous patch, also disable DPC here.
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
Signed-off-by: Kai-Heng Feng <[email protected]>
---
v8:
- Wording.
- Add more bug reports.
v7:
- Wording.
- Disable DPC completely (again) if power will be turned off
v6:
v5:
- Wording.
v4:
v3:
- No change.
v2:
- Only disable DPC IRQ.
- No more check on PME IRQ#.
drivers/pci/pcie/dpc.c | 57 ++++++++++++++++++++++++++++++++++--------
1 file changed, 46 insertions(+), 11 deletions(-)
diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index a668820696dc..7682ac4d6a89 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -14,6 +14,7 @@
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/pci.h>
+#include <linux/suspend.h>
#include "portdrv.h"
#include "../pci.h"
@@ -412,13 +413,34 @@ void pci_dpc_init(struct pci_dev *pdev)
}
}
+static void dpc_enable(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_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);
+}
+
+static void dpc_disable(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);
+}
+
#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 +455,7 @@ 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 +468,29 @@ static int dpc_probe(struct pcie_device *dev)
return status;
}
-static void dpc_remove(struct pcie_device *dev)
+static int dpc_suspend(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);
+ if (pci_ancestor_pr3_present(pdev) || pm_suspend_via_firmware())
+ dpc_disable(dev);
+
+ return 0;
+}
+
+static int dpc_resume(struct pcie_device *dev)
+{
+ struct pci_dev *pdev = dev->port;
+
+ if (pci_ancestor_pr3_present(pdev) || pm_resume_via_firmware())
+ dpc_enable(dev);
+
+ return 0;
+}
+
+static void dpc_remove(struct pcie_device *dev)
+{
+ dpc_disable(dev);
}
static struct pcie_port_service_driver dpcdriver = {
@@ -465,6 +498,8 @@ 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,
};
--
2.34.1
On 4/15/24 9:32 PM, Kai-Heng Feng wrote:
> In addition to nearest upstream bridge, driver may want to know if the
> entire hierarchy can be powered off to perform different action.
>
> So walk higher up the hierarchy to find out if any device has valid
> _PR3.
>
> The user will be introduced in next patch.
>
> Signed-off-by: Kai-Heng Feng <[email protected]>
> ---
Since it has been a while, I was not sure what this series is about.
IMO, it is better to include a cover letter with the summary of your
changes.
> v8:
> - No change.
>
> drivers/pci/pci.c | 16 ++++++++++++++++
> include/linux/pci.h | 2 ++
> 2 files changed, 18 insertions(+)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index e5f243dd4288..7a5662f116b8 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -6225,6 +6225,22 @@ bool pci_pr3_present(struct pci_dev *pdev)
> acpi_has_method(adev->handle, "_PR3");
> }
> EXPORT_SYMBOL_GPL(pci_pr3_present);
> +
> +bool pci_ancestor_pr3_present(struct pci_dev *pdev)
> +{
> + struct pci_dev *parent = pdev;
> +
> + if (acpi_disabled)
> + return false;
> +
> + while ((parent = pci_upstream_bridge(parent))) {
> + if (pci_pr3_present(pdev))
I think it should be "parent" here?
> + return true;
> + }
> +
> + return false;
> +}
> +EXPORT_SYMBOL_GPL(pci_ancestor_pr3_present);
> #endif
>
> /**
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 16493426a04f..cd71ebfd0f89 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -2620,10 +2620,12 @@ struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus);
> void
> pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *));
> bool pci_pr3_present(struct pci_dev *pdev);
> +bool pci_ancestor_pr3_present(struct pci_dev *pdev);
> #else
> static inline struct irq_domain *
> pci_host_bridge_acpi_msi_domain(struct pci_bus *bus) { return NULL; }
> static inline bool pci_pr3_present(struct pci_dev *pdev) { return false; }
> +static inline bool pci_ancestor_pr3_present(struct pci_dev *pdev) { return false; }
> #endif
>
> #ifdef CONFIG_EEH
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
On Thu, Apr 18, 2024 at 9:15 AM Kuppuswamy Sathyanarayanan
<[email protected]> wrote:
>
>
> On 4/15/24 9:32 PM, Kai-Heng Feng wrote:
> > In addition to nearest upstream bridge, driver may want to know if the
> > entire hierarchy can be powered off to perform different action.
> >
> > So walk higher up the hierarchy to find out if any device has valid
> > _PR3.
> >
> > The user will be introduced in next patch.
> >
> > Signed-off-by: Kai-Heng Feng <[email protected]>
> > ---
>
> Since it has been a while, I was not sure what this series is about.
>
> IMO, it is better to include a cover letter with the summary of your
> changes.
OK, will do in next revision.
>
>
> > v8:
> > - No change.
> >
> > drivers/pci/pci.c | 16 ++++++++++++++++
> > include/linux/pci.h | 2 ++
> > 2 files changed, 18 insertions(+)
> >
> > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> > index e5f243dd4288..7a5662f116b8 100644
> > --- a/drivers/pci/pci.c
> > +++ b/drivers/pci/pci.c
> > @@ -6225,6 +6225,22 @@ bool pci_pr3_present(struct pci_dev *pdev)
> > acpi_has_method(adev->handle, "_PR3");
> > }
> > EXPORT_SYMBOL_GPL(pci_pr3_present);
> > +
> > +bool pci_ancestor_pr3_present(struct pci_dev *pdev)
> > +{
> > + struct pci_dev *parent = pdev;
> > +
> > + if (acpi_disabled)
> > + return false;
> > +
> > + while ((parent = pci_upstream_bridge(parent))) {
> > + if (pci_pr3_present(pdev))
>
> I think it should be "parent" here?
Thanks for catching this.
But this patch will be dropped in next version for better simplicity.
Kai-Heng
>
> > + return true;
> > + }
> > +
> > + return false;
> > +}
> > +EXPORT_SYMBOL_GPL(pci_ancestor_pr3_present);
> > #endif
> >
> > /**
> > diff --git a/include/linux/pci.h b/include/linux/pci.h
> > index 16493426a04f..cd71ebfd0f89 100644
> > --- a/include/linux/pci.h
> > +++ b/include/linux/pci.h
> > @@ -2620,10 +2620,12 @@ struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus);
> > void
> > pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *));
> > bool pci_pr3_present(struct pci_dev *pdev);
> > +bool pci_ancestor_pr3_present(struct pci_dev *pdev);
> > #else
> > static inline struct irq_domain *
> > pci_host_bridge_acpi_msi_domain(struct pci_bus *bus) { return NULL; }
> > static inline bool pci_pr3_present(struct pci_dev *pdev) { return false; }
> > +static inline bool pci_ancestor_pr3_present(struct pci_dev *pdev) { return false; }
> > #endif
> >
> > #ifdef CONFIG_EEH
>
> --
> Sathyanarayanan Kuppuswamy
> Linux Kernel Developer
>