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PCI/PM: Always disable PTM for all devices during suspend

PATCH Superseded Bjorn Helgaas 4 participants 12 messages Sep 2, 2022 – Sep 3, 2022 PCI

v2 of 4 Superseded Latest is v4 →

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Bjorn Helgaas

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#0 lore raw

v2 cover PCI/PM: Always disable PTM for all devices during suspend

From: Bjorn Helgaas <[email protected]>

We currently disable PTM for Root Ports during suspend. Leaving PTM enabled for downstream devices causes UR errors if they send PTM Requests. The intent of this series is to:

- Unconditionally disable PTM during suspend (even if the driver saves its own state) by moving the disable from pci_prepare_to_sleep() to pci_pm_suspend().

- Disable PTM for all devices by removing the Root Port condition and doing it early in the suspend paths.

- Explicitly re-enable PTM during resume, which requires new support in pci_enable_ptm() for Root Ports and Switch Upstream Ports.

Bjorn Helgaas (3):
PCI/PTM: Preserve PTM Root Select
PCI/PTM: Implement pci_enable_ptm() for Root Ports, Switch Upstream
Ports
PCI/PM: Always disable PTM for all devices during suspend

 drivers/pci/pci-driver.c | 14 ++++++++++++++
 drivers/pci/pci.c        | 20 --------------------
 drivers/pci/pcie/ptm.c   | 36 ++++++++++++++++++++++++++++--------
 3 files changed, 42 insertions(+), 28 deletions(-)
Signature · 1 line
2.25.1
author
#1 lore raw

PATCH v2 1/3 PCI/PTM: Preserve PTM Root Select

From: Bjorn Helgaas <[email protected]>

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 <[email protected]>
Cc David E. Box <[email protected]>
---
 drivers/pci/pcie/ptm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/pci/pcie/ptm.c +1 -1
index 368a254e3124..b6a417247ce3 100644
@@ -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);
 }
Signature · 1 line
2.25.1
Reviewed-by on v2 1/3
#2 lore raw

Re: [PATCH v2 1/3] PCI/PTM: Preserve PTM Root Select

Hi,

Quoted 10 lines · Bjorn Helgaas

From: Bjorn Helgaas <[email protected]>

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.

Quoted 5 lines

Preserve Root Select to simplify re-enabling PTM.

Signed-off-by Bjorn Helgaas <[email protected]>
Cc David E. Box <[email protected]>

---

Reviewed-by Kuppuswamy Sathyanarayanan <[email protected]>
Quoted 16 lines
 drivers/pci/pcie/ptm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/pci/pcie/ptm.c +1 -1
index 368a254e3124..b6a417247ce3 100644
@@ -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);
 }
Signature · 2 lines
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
author
#3 lore raw

PATCH v2 2/3 PCI/PTM: Implement pci_enable_ptm() for Root Ports, Switch Upstream Ports

In reply to Bjorn Helgaas

From: Bjorn Helgaas <[email protected]>

Signed-off-by Bjorn Helgaas <[email protected]>
---
 drivers/pci/pcie/ptm.c | 34 +++++++++++++++++++++++++++-------
 1 file changed, 27 insertions(+), 7 deletions(-)
drivers/pci/pcie/ptm.c +27 -7
index b6a417247ce3..ad283818f37b 100644
@@ -167,11 +167,11 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity)
 	if (!pos)
 		return -EINVAL;
 
-	pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
-	if (!(cap & PCI_PTM_CAP_REQ))
-		return -EINVAL;
-
 	/*
+	 * Root Ports and Switch Upstream Ports have been configured
+	 * by pci_ptm_init(), so preserve their PCI_PTM_CTRL_ROOT and
+	 * granularity.
+	 *
 	 * For a PCIe Endpoint, PTM is only useful if the endpoint can
 	 * issue PTM requests to upstream devices that have PTM enabled.
 	 *

@@ -179,19 +179,39 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity)
 	 * device, so there must be some implementation-specific way to
 	 * associate the endpoint with a time source.
 	 */
-	if (pci_pcie_type(dev) == PCI_EXP_TYPE_ENDPOINT) {
+	if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
+	    pci_pcie_type(dev) == PCI_EXP_TYPE_UPSTREAM) {
+		if (pci_pcie_type(dev) == PCI_EXP_TYPE_UPSTREAM) {
+			ups = pci_upstream_bridge(dev);
+			if (!ups || !ups->ptm_enabled)
+				return -EINVAL;
+		}
+
+		pci_read_config_dword(dev, pos + PCI_PTM_CTRL, &ctrl);
+		ctrl |= PCI_PTM_CTRL_ENABLE;
+	} else if (pci_pcie_type(dev) == PCI_EXP_TYPE_ENDPOINT) {
+		pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
+		if (!(cap & PCI_PTM_CAP_REQ))
+			return -EINVAL;
+
 		ups = pci_upstream_bridge(dev);
 		if (!ups || !ups->ptm_enabled)
 			return -EINVAL;
 
 		dev->ptm_granularity = ups->ptm_granularity;
+		ctrl = PCI_PTM_CTRL_ENABLE;
+		ctrl |= dev->ptm_granularity << 8;
 	} else if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) {
+		pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
+		if (!(cap & PCI_PTM_CAP_REQ))
+			return -EINVAL;
+
 		dev->ptm_granularity = 0;
+		ctrl = PCI_PTM_CTRL_ENABLE;
+		ctrl |= dev->ptm_granularity << 8;
 	} else
 		return -EINVAL;
 
-	ctrl = PCI_PTM_CTRL_ENABLE;
-	ctrl |= dev->ptm_granularity << 8;
 	pci_write_config_dword(dev, pos + PCI_PTM_CTRL, ctrl);
 	dev->ptm_enabled = 1;
Signature · 1 line
2.25.1
#4 lore raw

Re: [PATCH v2 2/3] PCI/PTM: Implement pci_enable_ptm() for Root Ports, Switch Upstream Ports

Quoted 12 lines · Bjorn Helgaas

From: Bjorn Helgaas <[email protected]>

Signed-off-by Bjorn Helgaas <[email protected]>
---
 drivers/pci/pcie/ptm.c | 34 +++++++++++++++++++++++++++-------
 1 file changed, 27 insertions(+), 7 deletions(-)
drivers/pci/pcie/ptm.c +0 -0
index b6a417247ce3..ad283818f37b 100644

drivers/pci/pcie/ptm.c int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) · line 173

Quoted 7 lines
drivers/pci/pcie/ptm.c +0 -4
@@ -167,11 +167,11 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity)
 	if (!pos)
 		return -EINVAL;
 
-	pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
-	if (!(cap & PCI_PTM_CAP_REQ))
-		return -EINVAL;
-

May be saving PCI_PTM_CAP_REQ enabled state here and using it below only for endpoints checks will reduce the code duplication?

Quoted 12 lines
drivers/pci/pcie/ptm.c +4 -0
 	/*
+	 * Root Ports and Switch Upstream Ports have been configured
+	 * by pci_ptm_init(), so preserve their PCI_PTM_CTRL_ROOT and
+	 * granularity.
+	 *
 	 * For a PCIe Endpoint, PTM is only useful if the endpoint can
 	 * issue PTM requests to upstream devices that have PTM enabled.
 	 *

@@ -179,19 +179,39 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity)
 	 * device, so there must be some implementation-specific way to
 	 * associate the endpoint with a time source.
 	 */

drivers/pci/pcie/ptm.c int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) · line 190

Quoted 10 lines
drivers/pci/pcie/ptm.c +9 -1
-	if (pci_pcie_type(dev) == PCI_EXP_TYPE_ENDPOINT) {
+	if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
+	    pci_pcie_type(dev) == PCI_EXP_TYPE_UPSTREAM) {
+		if (pci_pcie_type(dev) == PCI_EXP_TYPE_UPSTREAM) {
+			ups = pci_upstream_bridge(dev);
+			if (!ups || !ups->ptm_enabled)
+				return -EINVAL;
+		}
+
+		pci_read_config_dword(dev, pos + PCI_PTM_CTRL, &ctrl);

Why read PCI_PTM_CTRL state only for root and upstream ports? The same logic will work for endpoints and RC endpoints right?

What not use dev->ptm_granularity for root ports?

Quoted 29 lines
drivers/pci/pcie/ptm.c +14 -2
+		ctrl |= PCI_PTM_CTRL_ENABLE;
+	} else if (pci_pcie_type(dev) == PCI_EXP_TYPE_ENDPOINT) {
+		pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
+		if (!(cap & PCI_PTM_CAP_REQ))
+			return -EINVAL;
+
 		ups = pci_upstream_bridge(dev);
 		if (!ups || !ups->ptm_enabled)
 			return -EINVAL;
 
 		dev->ptm_granularity = ups->ptm_granularity;
+		ctrl = PCI_PTM_CTRL_ENABLE;
+		ctrl |= dev->ptm_granularity << 8;
 	} else if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) {
+		pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
+		if (!(cap & PCI_PTM_CAP_REQ))
+			return -EINVAL;
+
 		dev->ptm_granularity = 0;
+		ctrl = PCI_PTM_CTRL_ENABLE;
+		ctrl |= dev->ptm_granularity << 8;
 	} else
 		return -EINVAL;
 
-	ctrl = PCI_PTM_CTRL_ENABLE;
-	ctrl |= dev->ptm_granularity << 8;
 	pci_write_config_dword(dev, pos + PCI_PTM_CTRL, ctrl);
 	dev->ptm_enabled = 1;
Signature · 2 lines
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
#5 lore raw

Re: [PATCH v2 2/3] PCI/PTM: Implement pci_enable_ptm() for Root Ports, Switch Upstream Ports

In reply to Bjorn Helgaas
Quoted 55 lines · Bjorn Helgaas

From: Bjorn Helgaas <[email protected]>

Signed-off-by Bjorn Helgaas <[email protected]>
---
 drivers/pci/pcie/ptm.c | 34 +++++++++++++++++++++++++++-------
 1 file changed, 27 insertions(+), 7 deletions(-)
drivers/pci/pcie/ptm.c +21 -5
index b6a417247ce3..ad283818f37b 100644
@@ -167,11 +167,11 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity)
        if (!pos)
                return -EINVAL;
 
-       pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
-       if (!(cap & PCI_PTM_CAP_REQ))
-               return -EINVAL;
-
        /*
+        * Root Ports and Switch Upstream Ports have been configured
+        * by pci_ptm_init(), so preserve their PCI_PTM_CTRL_ROOT and
+        * granularity.
+        *
         * For a PCIe Endpoint, PTM is only useful if the endpoint can
         * issue PTM requests to upstream devices that have PTM enabled.
         *

@@ -179,19 +179,39 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity)
         * device, so there must be some implementation-specific way to
         * associate the endpoint with a time source.
         */
-       if (pci_pcie_type(dev) == PCI_EXP_TYPE_ENDPOINT) {
+       if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
+           pci_pcie_type(dev) == PCI_EXP_TYPE_UPSTREAM) {
+               if (pci_pcie_type(dev) == PCI_EXP_TYPE_UPSTREAM) {
+                       ups = pci_upstream_bridge(dev);
+                       if (!ups || !ups->ptm_enabled)
+                               return -EINVAL;
+               }
+
+               pci_read_config_dword(dev, pos + PCI_PTM_CTRL, &ctrl);
+               ctrl |= PCI_PTM_CTRL_ENABLE;
+       } else if (pci_pcie_type(dev) == PCI_EXP_TYPE_ENDPOINT) {
+               pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
+               if (!(cap & PCI_PTM_CAP_REQ))
+                       return -EINVAL;
+
                ups = pci_upstream_bridge(dev);
                if (!ups || !ups->ptm_enabled)
                        return -EINVAL;
 
                dev->ptm_granularity = ups->ptm_granularity;
+               ctrl = PCI_PTM_CTRL_ENABLE;
+               ctrl |= dev->ptm_granularity << 8;

drivers/pci/pcie/ptm.c int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) · line 213

Quoted 10 lines
drivers/pci/pcie/ptm.c +6 -0
        } else if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) {
+               pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
+               if (!(cap & PCI_PTM_CAP_REQ))
+                       return -EINVAL;
+
                dev->ptm_granularity = 0;
+               ctrl = PCI_PTM_CTRL_ENABLE;
+               ctrl |= dev->ptm_granularity << 8;
        } else
                return -EINVAL;

I would do

if ((pci_pcie_type(dev) == PCI_EXP_TYPE_UPSTREAM || pci_pcie_type(dev)

== PCI_EXP_TYPE_ENDPOINT)) {
        ups = pci_upstream_bridge(dev);
        if (!ups || !ups->ptm_enabled)
                return -EINVAL;

        dev->ptm_granularity = ups->ptm_granularity;
}

switch(pci_pcie_type(dev)) {
case PCI_EXP_TYPE_ROOT_PORT:
case PCI_EXP_TYPE_UPSTREAM:

        pci_read_config_dword(dev, pos + PCI_PTM_CTRL, &ctrl);
        ctrl |= PCI_PTM_CTRL_ENABLE;
        break;
case PCI_EXP_TYPE_ENDPOINT:
case PCI_EXP_TYPE_RC_END:
        ctrl = PCI_PTM_CTRL_ENABLE;
        break;
default:
        return -EINVAL;
}

drivers/pci/pcie/ptm.c int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) · line 194

Quoted 3 lines
drivers/pci/pcie/ptm.c +0 -2
-       ctrl = PCI_PTM_CTRL_ENABLE;
-       ctrl |= dev->ptm_granularity << 8;

And I wouldn't remove the line above.

Note that for root ports dev->ptm_granularity must be set and reflect the register setting or else the code wouldn't have worked for downstream components.

Quoted 4 lines
drivers/pci/pcie/ptm.c +0 -1
        pci_write_config_dword(dev, pos + PCI_PTM_CTRL, ctrl);
        dev->ptm_enabled = 1;
 
--
#6 lore raw

Re: [PATCH v2 2/3] PCI/PTM: Implement pci_enable_ptm() for Root Ports, Switch Upstream Ports

Quoted 79 lines · Rafael J. Wysocki
Quoted 55 lines · Bjorn Helgaas

From: Bjorn Helgaas <[email protected]>

Signed-off-by Bjorn Helgaas <[email protected]>
---
 drivers/pci/pcie/ptm.c | 34 +++++++++++++++++++++++++++-------
 1 file changed, 27 insertions(+), 7 deletions(-)
drivers/pci/pcie/ptm.c +21 -5
index b6a417247ce3..ad283818f37b 100644
@@ -167,11 +167,11 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity)
        if (!pos)
                return -EINVAL;
 
-       pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
-       if (!(cap & PCI_PTM_CAP_REQ))
-               return -EINVAL;
-
        /*
+        * Root Ports and Switch Upstream Ports have been configured
+        * by pci_ptm_init(), so preserve their PCI_PTM_CTRL_ROOT and
+        * granularity.
+        *
         * For a PCIe Endpoint, PTM is only useful if the endpoint can
         * issue PTM requests to upstream devices that have PTM enabled.
         *

@@ -179,19 +179,39 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity)
         * device, so there must be some implementation-specific way to
         * associate the endpoint with a time source.
         */
-       if (pci_pcie_type(dev) == PCI_EXP_TYPE_ENDPOINT) {
+       if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
+           pci_pcie_type(dev) == PCI_EXP_TYPE_UPSTREAM) {
+               if (pci_pcie_type(dev) == PCI_EXP_TYPE_UPSTREAM) {
+                       ups = pci_upstream_bridge(dev);
+                       if (!ups || !ups->ptm_enabled)
+                               return -EINVAL;
+               }
+
+               pci_read_config_dword(dev, pos + PCI_PTM_CTRL, &ctrl);
+               ctrl |= PCI_PTM_CTRL_ENABLE;
+       } else if (pci_pcie_type(dev) == PCI_EXP_TYPE_ENDPOINT) {
+               pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
+               if (!(cap & PCI_PTM_CAP_REQ))
+                       return -EINVAL;
+
                ups = pci_upstream_bridge(dev);
                if (!ups || !ups->ptm_enabled)
                        return -EINVAL;
 
                dev->ptm_granularity = ups->ptm_granularity;
+               ctrl = PCI_PTM_CTRL_ENABLE;
+               ctrl |= dev->ptm_granularity << 8;

drivers/pci/pcie/ptm.c int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) · line 213

Quoted 10 lines
drivers/pci/pcie/ptm.c +6 -0
        } else if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) {
+               pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
+               if (!(cap & PCI_PTM_CAP_REQ))
+                       return -EINVAL;
+
                dev->ptm_granularity = 0;
+               ctrl = PCI_PTM_CTRL_ENABLE;
+               ctrl |= dev->ptm_granularity << 8;
        } else
                return -EINVAL;

I would do

if ((pci_pcie_type(dev) == PCI_EXP_TYPE_UPSTREAM || pci_pcie_type(dev)

== PCI_EXP_TYPE_ENDPOINT)) {
        ups = pci_upstream_bridge(dev);
        if (!ups || !ups->ptm_enabled)
                return -EINVAL;

        dev->ptm_granularity = ups->ptm_granularity;
}
Quoted 8 lines

switch(pci_pcie_type(dev)) {
case PCI_EXP_TYPE_ROOT_PORT:
case PCI_EXP_TYPE_UPSTREAM:

        pci_read_config_dword(dev, pos + PCI_PTM_CTRL, &ctrl);
        ctrl |= PCI_PTM_CTRL_ENABLE;
        break;

case PCI_EXP_TYPE_ENDPOINT:
case PCI_EXP_TYPE_RC_END:

I missed the cap check here, sorry.

Quoted 20 lines
        ctrl = PCI_PTM_CTRL_ENABLE;
        break;
default:
        return -EINVAL;
}

drivers/pci/pcie/ptm.c int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) · line 194

Quoted 3 lines
drivers/pci/pcie/ptm.c +0 -2
-       ctrl = PCI_PTM_CTRL_ENABLE;
-       ctrl |= dev->ptm_granularity << 8;

And I wouldn't remove the line above.

Note that for root ports dev->ptm_granularity must be set and reflect the register setting or else the code wouldn't have worked for downstream components.

Quoted 4 lines
drivers/pci/pcie/ptm.c +0 -1
        pci_write_config_dword(dev, pos + PCI_PTM_CTRL, ctrl);
        dev->ptm_enabled = 1;
 
--
author
#7 lore raw

PATCH v2 3/3 PCI/PM: Always disable PTM for all devices during suspend

In reply to Bjorn Helgaas

From: Bjorn Helgaas <[email protected]>

We want to disable PTM on Root Ports because that allows some chips, e.g., Intel mobile chips since Coffee Lake, to enter a lower-power PM state.

That means we also have to disable PTM on downstream devices. PCIe r6.0, sec 2.2.8, recommends that functions support generation of messages in non-D0 states, so we have to assume Switch Upstream Ports or Endpoints may send PTM Requests while in D1, D2, and D3hot. A PTM message received by a Downstream Port (including a Root Port) with PTM disabled must be treated as an Unsupported Request (sec 6.21.3).

PTM was previously disabled only for Root Ports, and it was disabled in pci_prepare_to_sleep(), which is not called at all if a driver supports legacy PM or does its own state saving.

Instead, disable PTM early in pci_pm_suspend() and pci_pm_runtime_suspend() so we do it in all cases.

Previously PTM was disabled *after* saving device state, so the state restore on resume automatically re-enabled it. Since we now disable PTM *before* saving state, we must explicitly re-enable it.

Here's a sample of errors that occur when PTM is disabled only on the Root Port. With this topology:

0000:00:1d.0 Root Port to [bus 08-71]
0000:08:00.0 Switch Upstream Port to [bus 09-71]

Kai-Heng reported errors like this:

pcieport 0000:00:1d.0: AER: Uncorrected (Non-Fatal) error received: 0000:00:1d.0
pcieport 0000:00:1d.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, (Requester ID)
pcieport 0000:00:1d.0: device [8086:7ab0] error status/mask=00100000/00004000
pcieport 0000:00:1d.0: [20] UnsupReq (First)
pcieport 0000:00:1d.0: AER: TLP Header: 34000000 08000052 00000000 00000000

Decoding TLP header 0x34...... (0011 0100b) and 0x08000052:

  Fmt                         001b  4 DW header, no data
  Type                     1 0100b  Msg (Local - Terminate at Receiver)
  Requester ID  0x0800              Bus 08 Devfn 00.0
  Message Code    0x52  0101 0010b  PTM Request

The 00:1d.0 Root Port logged an Unsupported Request error when it received a PTM Request with Requester ID 08:00.0.

Fixes a697f072f5da ("PCI: Disable PTM during suspend to save power")

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215453
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=216210
Based-on: https://lore.kernel.org/r/[email protected]

Based-on-patch-by Kai-Heng Feng <[email protected]>
Reported-by Kai-Heng Feng <[email protected]>
Signed-off-by Bjorn Helgaas <[email protected]>
---
 drivers/pci/pci-driver.c | 14 ++++++++++++++
 drivers/pci/pci.c        | 20 --------------------
 2 files changed, 14 insertions(+), 20 deletions(-)
drivers/pci/pci-driver.c +14 -0
index 2815922ac525..115febaa7e0b 100644
@@ -772,6 +772,12 @@ static int pci_pm_suspend(struct device *dev)
 	struct pci_dev *pci_dev = to_pci_dev(dev);
 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 
+	/*
+	 * Disabling PTM allows some systems, e.g., Intel mobile chips
+	 * since Coffee Lake, to enter a lower-power PM state.
+	 */
+	pci_disable_ptm(pci_dev);
+
 	pci_dev->skip_bus_pm = false;
 
 	if (pci_has_legacy_pm_support(pci_dev))

@@ -982,6 +988,9 @@ static int pci_pm_resume(struct device *dev)
 	if (pci_dev->state_saved)
 		pci_restore_standard_config(pci_dev);
 
+	if (pci_dev->ptm_enabled)
+		pci_enable_ptm(pci_dev, NULL);
+
 	if (pci_has_legacy_pm_support(pci_dev))
 		return pci_legacy_resume(dev);
 

@@ -1269,6 +1278,8 @@ static int pci_pm_runtime_suspend(struct device *dev)
 	pci_power_t prev = pci_dev->current_state;
 	int error;
 
+	pci_disable_ptm(pci_dev);
+
 	/*
 	 * If pci_dev->driver is not set (unbound), we leave the device in D0,
 	 * but it may go to D3cold when the bridge above it runtime suspends.

@@ -1331,6 +1342,9 @@ static int pci_pm_runtime_resume(struct device *dev)
 	 */
 	pci_pm_default_resume_early(pci_dev);
 
+	if (pci_dev->ptm_enabled)
+		pci_enable_ptm(pci_dev, NULL);
+
 	if (!pci_dev->driver)
 		return 0;
drivers/pci/pci.c +0 -20
index 95bc329e74c0..b0e2968c8cca 100644
@@ -2706,16 +2706,6 @@ int pci_prepare_to_sleep(struct pci_dev *dev)
 	if (target_state == PCI_POWER_ERROR)
 		return -EIO;
 
-	/*
-	 * There are systems (for example, Intel mobile chips since Coffee
-	 * Lake) where the power drawn while suspended can be significantly
-	 * reduced by disabling PTM on PCIe root ports as this allows the
-	 * port to enter a lower-power PM state and the SoC to reach a
-	 * lower-power idle state as a whole.
-	 */
-	if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
-		pci_disable_ptm(dev);
-
 	pci_enable_wake(dev, target_state, wakeup);
 
 	error = pci_set_power_state(dev, target_state);

@@ -2764,16 +2754,6 @@ int pci_finish_runtime_suspend(struct pci_dev *dev)
 	if (target_state == PCI_POWER_ERROR)
 		return -EIO;
 
-	/*
-	 * There are systems (for example, Intel mobile chips since Coffee
-	 * Lake) where the power drawn while suspended can be significantly
-	 * reduced by disabling PTM on PCIe root ports as this allows the
-	 * port to enter a lower-power PM state and the SoC to reach a
-	 * lower-power idle state as a whole.
-	 */
-	if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
-		pci_disable_ptm(dev);
-
 	__pci_enable_wake(dev, target_state, pci_dev_run_wake(dev));
 
 	error = pci_set_power_state(dev, target_state);
Signature · 1 line
2.25.1
#8 lore raw
Quoted 64 lines · Bjorn Helgaas

From: Bjorn Helgaas <[email protected]>

We want to disable PTM on Root Ports because that allows some chips, e.g., Intel mobile chips since Coffee Lake, to enter a lower-power PM state.

That means we also have to disable PTM on downstream devices. PCIe r6.0, sec 2.2.8, recommends that functions support generation of messages in non-D0 states, so we have to assume Switch Upstream Ports or Endpoints may send PTM Requests while in D1, D2, and D3hot. A PTM message received by a Downstream Port (including a Root Port) with PTM disabled must be treated as an Unsupported Request (sec 6.21.3).

PTM was previously disabled only for Root Ports, and it was disabled in pci_prepare_to_sleep(), which is not called at all if a driver supports legacy PM or does its own state saving.

Instead, disable PTM early in pci_pm_suspend() and pci_pm_runtime_suspend() so we do it in all cases.

Previously PTM was disabled *after* saving device state, so the state restore on resume automatically re-enabled it. Since we now disable PTM *before* saving state, we must explicitly re-enable it.

Here's a sample of errors that occur when PTM is disabled only on the Root Port. With this topology:

0000:00:1d.0 Root Port to [bus 08-71]
0000:08:00.0 Switch Upstream Port to [bus 09-71]

Kai-Heng reported errors like this:

pcieport 0000:00:1d.0: AER: Uncorrected (Non-Fatal) error received: 0000:00:1d.0
pcieport 0000:00:1d.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, (Requester ID)
pcieport 0000:00:1d.0: device [8086:7ab0] error status/mask=00100000/00004000
pcieport 0000:00:1d.0: [20] UnsupReq (First)
pcieport 0000:00:1d.0: AER: TLP Header: 34000000 08000052 00000000 00000000

Decoding TLP header 0x34...... (0011 0100b) and 0x08000052:

  Fmt                         001b  4 DW header, no data
  Type                     1 0100b  Msg (Local - Terminate at Receiver)
  Requester ID  0x0800              Bus 08 Devfn 00.0
  Message Code    0x52  0101 0010b  PTM Request

The 00:1d.0 Root Port logged an Unsupported Request error when it received a PTM Request with Requester ID 08:00.0.

Fixes a697f072f5da ("PCI: Disable PTM during suspend to save power")

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215453
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=216210
Based-on: https://lore.kernel.org/r/[email protected]

Based-on-patch-by Kai-Heng Feng <[email protected]>
Reported-by Kai-Heng Feng <[email protected]>
Signed-off-by Bjorn Helgaas <[email protected]>
---
 drivers/pci/pci-driver.c | 14 ++++++++++++++
 drivers/pci/pci.c        | 20 --------------------
 2 files changed, 14 insertions(+), 20 deletions(-)
drivers/pci/pci-driver.c +0 -0
index 2815922ac525..115febaa7e0b 100644

drivers/pci/pci-driver.c static int pci_pm_suspend(struct device *dev) · line 779

Quoted 8 lines
drivers/pci/pci-driver.c +5 -0
@@ -772,6 +772,12 @@ static int pci_pm_suspend(struct device *dev)
 	struct pci_dev *pci_dev = to_pci_dev(dev);
 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 
+	/*
+	 * Disabling PTM allows some systems, e.g., Intel mobile chips
+	 * since Coffee Lake, to enter a lower-power PM state.
+	 */
+	pci_disable_ptm(pci_dev);

I think you can use "if (pci_dev->ptm_enabled)" check for pci_disable_ptm() as well. This will avoid unnecessary checks in pci_disable_ptm().

Quoted 71 lines
drivers/pci/pci-driver.c +9 -0
+
 	pci_dev->skip_bus_pm = false;
 
 	if (pci_has_legacy_pm_support(pci_dev))

@@ -982,6 +988,9 @@ static int pci_pm_resume(struct device *dev)
 	if (pci_dev->state_saved)
 		pci_restore_standard_config(pci_dev);
 
+	if (pci_dev->ptm_enabled)
+		pci_enable_ptm(pci_dev, NULL);
+
 	if (pci_has_legacy_pm_support(pci_dev))
 		return pci_legacy_resume(dev);
 

@@ -1269,6 +1278,8 @@ static int pci_pm_runtime_suspend(struct device *dev)
 	pci_power_t prev = pci_dev->current_state;
 	int error;
 
+	pci_disable_ptm(pci_dev);
+
 	/*
 	 * If pci_dev->driver is not set (unbound), we leave the device in D0,
 	 * but it may go to D3cold when the bridge above it runtime suspends.

@@ -1331,6 +1342,9 @@ static int pci_pm_runtime_resume(struct device *dev)
 	 */
 	pci_pm_default_resume_early(pci_dev);
 
+	if (pci_dev->ptm_enabled)
+		pci_enable_ptm(pci_dev, NULL);
+
 	if (!pci_dev->driver)
 		return 0;
drivers/pci/pci.c +0 -20
index 95bc329e74c0..b0e2968c8cca 100644
@@ -2706,16 +2706,6 @@ int pci_prepare_to_sleep(struct pci_dev *dev)
 	if (target_state == PCI_POWER_ERROR)
 		return -EIO;
 
-	/*
-	 * There are systems (for example, Intel mobile chips since Coffee
-	 * Lake) where the power drawn while suspended can be significantly
-	 * reduced by disabling PTM on PCIe root ports as this allows the
-	 * port to enter a lower-power PM state and the SoC to reach a
-	 * lower-power idle state as a whole.
-	 */
-	if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
-		pci_disable_ptm(dev);
-
 	pci_enable_wake(dev, target_state, wakeup);
 
 	error = pci_set_power_state(dev, target_state);

@@ -2764,16 +2754,6 @@ int pci_finish_runtime_suspend(struct pci_dev *dev)
 	if (target_state == PCI_POWER_ERROR)
 		return -EIO;
 
-	/*
-	 * There are systems (for example, Intel mobile chips since Coffee
-	 * Lake) where the power drawn while suspended can be significantly
-	 * reduced by disabling PTM on PCIe root ports as this allows the
-	 * port to enter a lower-power PM state and the SoC to reach a
-	 * lower-power idle state as a whole.
-	 */
-	if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
-		pci_disable_ptm(dev);
-
 	__pci_enable_wake(dev, target_state, pci_dev_run_wake(dev));
 
 	error = pci_set_power_state(dev, target_state);
Signature · 2 lines
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
#9 lore raw
Quoted 71 lines · Sathyanarayanan Kuppuswamy
Quoted 67 lines · Bjorn Helgaas

From: Bjorn Helgaas <[email protected]>

We want to disable PTM on Root Ports because that allows some chips, e.g., Intel mobile chips since Coffee Lake, to enter a lower-power PM state.

That means we also have to disable PTM on downstream devices. PCIe r6.0, sec 2.2.8, recommends that functions support generation of messages in non-D0 states, so we have to assume Switch Upstream Ports or Endpoints may send PTM Requests while in D1, D2, and D3hot. A PTM message received by a Downstream Port (including a Root Port) with PTM disabled must be treated as an Unsupported Request (sec 6.21.3).

PTM was previously disabled only for Root Ports, and it was disabled in pci_prepare_to_sleep(), which is not called at all if a driver supports legacy PM or does its own state saving.

Instead, disable PTM early in pci_pm_suspend() and pci_pm_runtime_suspend() so we do it in all cases.

Previously PTM was disabled *after* saving device state, so the state restore on resume automatically re-enabled it. Since we now disable PTM *before* saving state, we must explicitly re-enable it.

Here's a sample of errors that occur when PTM is disabled only on the Root Port. With this topology:

0000:00:1d.0 Root Port to [bus 08-71]
0000:08:00.0 Switch Upstream Port to [bus 09-71]

Kai-Heng reported errors like this:

pcieport 0000:00:1d.0: AER: Uncorrected (Non-Fatal) error received: 0000:00:1d.0
pcieport 0000:00:1d.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, (Requester ID)
pcieport 0000:00:1d.0: device [8086:7ab0] error status/mask=00100000/00004000
pcieport 0000:00:1d.0: [20] UnsupReq (First)
pcieport 0000:00:1d.0: AER: TLP Header: 34000000 08000052 00000000 00000000

Decoding TLP header 0x34...... (0011 0100b) and 0x08000052:

  Fmt                         001b  4 DW header, no data
  Type                     1 0100b  Msg (Local - Terminate at Receiver)
  Requester ID  0x0800              Bus 08 Devfn 00.0
  Message Code    0x52  0101 0010b  PTM Request

The 00:1d.0 Root Port logged an Unsupported Request error when it received a PTM Request with Requester ID 08:00.0.

Fixes a697f072f5da ("PCI: Disable PTM during suspend to save power")

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215453
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=216210
Based-on: https://lore.kernel.org/r/[email protected]

Based-on-patch-by Kai-Heng Feng <[email protected]>
Reported-by Kai-Heng Feng <[email protected]>
Signed-off-by Bjorn Helgaas <[email protected]>
---
 drivers/pci/pci-driver.c | 14 ++++++++++++++
 drivers/pci/pci.c        | 20 --------------------
 2 files changed, 14 insertions(+), 20 deletions(-)
drivers/pci/pci-driver.c +0 -0
index 2815922ac525..115febaa7e0b 100644
@@ -772,6 +772,12 @@ static int pci_pm_suspend(struct device *dev)
      struct pci_dev *pci_dev = to_pci_dev(dev);
      const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
Quoted 8 lines

drivers/pci/pci-driver.c static int pci_pm_suspend(struct device *dev) · line 779

Quoted 5 lines
drivers/pci/pci-driver.c +5 -0
+     /*
+      * Disabling PTM allows some systems, e.g., Intel mobile chips
+      * since Coffee Lake, to enter a lower-power PM state.
+      */
+     pci_disable_ptm(pci_dev);

I think you can use "if (pci_dev->ptm_enabled)" check for pci_disable_ptm() as well. This will avoid unnecessary checks in pci_disable_ptm().

Or use that check in pci_disable_ptm() instead of the pci_is_pcie() one.

Also, I would remae pci_disable_ptm() to pci_suspend_ptm() (because its role is to temporarily disable PTM for system-wide suspend) and introduc pci_resume_ptm() that will do

if (pci_dev->ptm_enabled)

        pci_enable_ptm(pci_dev, NULL);
Quoted 75 lines
Quoted 61 lines
drivers/pci/pci-driver.c +9 -0
+
      pci_dev->skip_bus_pm = false;
 
      if (pci_has_legacy_pm_support(pci_dev))

@@ -982,6 +988,9 @@ static int pci_pm_resume(struct device *dev)
      if (pci_dev->state_saved)
              pci_restore_standard_config(pci_dev);
 
+     if (pci_dev->ptm_enabled)
+             pci_enable_ptm(pci_dev, NULL);
+
      if (pci_has_legacy_pm_support(pci_dev))
              return pci_legacy_resume(dev);
 

@@ -1269,6 +1278,8 @@ static int pci_pm_runtime_suspend(struct device *dev)
      pci_power_t prev = pci_dev->current_state;
      int error;
 
+     pci_disable_ptm(pci_dev);
+
      /*
       * If pci_dev->driver is not set (unbound), we leave the device in D0,
       * but it may go to D3cold when the bridge above it runtime suspends.

@@ -1331,6 +1342,9 @@ static int pci_pm_runtime_resume(struct device *dev)
       */
      pci_pm_default_resume_early(pci_dev);
 
+     if (pci_dev->ptm_enabled)
+             pci_enable_ptm(pci_dev, NULL);
+
      if (!pci_dev->driver)
              return 0;
drivers/pci/pci.c +0 -13
index 95bc329e74c0..b0e2968c8cca 100644
@@ -2706,16 +2706,6 @@ int pci_prepare_to_sleep(struct pci_dev *dev)
      if (target_state == PCI_POWER_ERROR)
              return -EIO;
 
-     /*
-      * There are systems (for example, Intel mobile chips since Coffee
-      * Lake) where the power drawn while suspended can be significantly
-      * reduced by disabling PTM on PCIe root ports as this allows the
-      * port to enter a lower-power PM state and the SoC to reach a
-      * lower-power idle state as a whole.
-      */
-     if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
-             pci_disable_ptm(dev);
-
      pci_enable_wake(dev, target_state, wakeup);
 
      error = pci_set_power_state(dev, target_state);

@@ -2764,16 +2754,6 @@ int pci_finish_runtime_suspend(struct pci_dev *dev)
      if (target_state == PCI_POWER_ERROR)
              return -EIO;
 
-     /*
-      * There are systems (for example, Intel mobile chips since Coffee
-      * Lake) where the power drawn while suspended can be significantly

drivers/pci/pci.c int pci_finish_runtime_suspend(struct pci_dev *dev) · line 2759

Quoted 10 lines
drivers/pci/pci.c +0 -7
-      * reduced by disabling PTM on PCIe root ports as this allows the
-      * port to enter a lower-power PM state and the SoC to reach a
-      * lower-power idle state as a whole.
-      */
-     if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
-             pci_disable_ptm(dev);
-
      __pci_enable_wake(dev, target_state, pci_dev_run_wake(dev));
 
      error = pci_set_power_state(dev, target_state);

--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer

build bot
#10 lore raw
In reply to Bjorn Helgaas
I love your patch! Yet something to improve:

Hi Bjorn,

I love your patch! Yet something to improve:

[auto build test ERROR on helgaas-pci/next]
[also build test ERROR on linus/master v6.0-rc3 next-20220901] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Bjorn-Helgaas/PCI-PM-Always-disable-PTM-for-all-devices-during-suspend/20220903-073808
base:   https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next
config: riscv-randconfig-r042-20220901 (https://download.01.org/0day-ci/archive/20220903/[email protected]/config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project c55b41d5199d2394dd6cdb8f52180d8b81d809d4)

reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross
# install riscv cross compiling tool for clang build
# apt-get install binutils-riscv64-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/809e1c954b459ee37193c4ab9fa843243fbd7fa9
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Bjorn-Helgaas/PCI-PM-Always-disable-PTM-for-all-devices-during-suspend/20220903-073808 git checkout 809e1c954b459ee37193c4ab9fa843243fbd7fa9
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash drivers/pci/

If you fix the issue, kindly add following tag where applicable

Reported-by kernel test robot <[email protected]>

All errors (new ones prefixed by >>):

>> drivers/pci/pci-driver.c:1350:15: error: no member named 'ptm_enabled' in 'struct pci_dev'
           if (pci_dev->ptm_enabled)
               ~~~~~~~  ^

1 error generated.

vim +1350 drivers/pci/pci-driver.c

1335
1336 static int pci_pm_runtime_resume(struct device *dev)
1337 {
1338 struct pci_dev *pci_dev = to_pci_dev(dev);
1339 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1340 pci_power_t prev_state = pci_dev->current_state;
1341 int error = 0;
1342
1343 /*
1344 * Restoring config space is necessary even if the device is not bound
1345 * to a driver because although we left it in D0, it may have gone to
1346 * D3cold when the bridge above it runtime suspended.
1347 */
1348 pci_pm_default_resume_early(pci_dev);
1349

> 1350		if (pci_dev->ptm_enabled)

1351 pci_enable_ptm(pci_dev, NULL);
1352
1353 if (!pci_dev->driver)
1354 return 0;
1355
1356 pci_fixup_device(pci_fixup_resume_early, pci_dev);
1357 pci_pm_default_resume(pci_dev);
1358
1359 if (prev_state == PCI_D3cold)
1360 pci_pm_bridge_power_up_actions(pci_dev);
1361
1362 if (pm && pm->runtime_resume)
1363 error = pm->runtime_resume(dev);
1364
1365 return error;
1366 }
1367

Signature · 2 lines
0-DAY CI Kernel Test Service
https://01.org/lkp
build bot
#11 lore raw
In reply to Bjorn Helgaas
I love your patch! Yet something to improve:

Hi Bjorn,

I love your patch! Yet something to improve:

[auto build test ERROR on helgaas-pci/next]
[also build test ERROR on linus/master v6.0-rc3 next-20220901] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Bjorn-Helgaas/PCI-PM-Always-disable-PTM-for-all-devices-during-suspend/20220903-073808
base:   https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next
config: x86_64-randconfig-a015 (https://download.01.org/0day-ci/archive/20220903/[email protected]/config)
compiler: gcc-11 (Debian 11.3.0-5) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/809e1c954b459ee37193c4ab9fa843243fbd7fa9
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Bjorn-Helgaas/PCI-PM-Always-disable-PTM-for-all-devices-during-suspend/20220903-073808
        git checkout 809e1c954b459ee37193c4ab9fa843243fbd7fa9
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable

Reported-by kernel test robot <[email protected]>

All errors (new ones prefixed by >>):

drivers/pci/pci-driver.c: In function 'pci_pm_runtime_resume':

>> drivers/pci/pci-driver.c:1350:22: error: 'struct pci_dev' has no member named 'ptm_enabled'; did you mean 'ats_enabled'?
    1350 |         if (pci_dev->ptm_enabled)
         |                      ^~~~~~~~~~~
         |                      ats_enabled

vim +1350 drivers/pci/pci-driver.c

1335
1336 static int pci_pm_runtime_resume(struct device *dev)
1337 {
1338 struct pci_dev *pci_dev = to_pci_dev(dev);
1339 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1340 pci_power_t prev_state = pci_dev->current_state;
1341 int error = 0;
1342
1343 /*
1344 * Restoring config space is necessary even if the device is not bound
1345 * to a driver because although we left it in D0, it may have gone to
1346 * D3cold when the bridge above it runtime suspended.
1347 */
1348 pci_pm_default_resume_early(pci_dev);
1349

> 1350		if (pci_dev->ptm_enabled)

1351 pci_enable_ptm(pci_dev, NULL);
1352
1353 if (!pci_dev->driver)
1354 return 0;
1355
1356 pci_fixup_device(pci_fixup_resume_early, pci_dev);
1357 pci_pm_default_resume(pci_dev);
1358
1359 if (prev_state == PCI_D3cold)
1360 pci_pm_bridge_power_up_actions(pci_dev);
1361
1362 if (pm && pm->runtime_resume)
1363 error = pm->runtime_resume(dev);
1364
1365 return error;
1366 }
1367

Signature · 2 lines
0-DAY CI Kernel Test Service
https://01.org/lkp