[PATCH v3 0/4] PCI/ASPM: add sysfs attributes for controlling ASPM

[PATCH v3 0/4] PCI/ASPM: add sysfs attributes for controlling ASPM

[Heiner Kallweit]

Background of this extension is a problem with the r8169 network driver.
Several combinations of board chipsets and network chip versions have
problems if ASPM is enabled, therefore we have to disable ASPM per
default. However especially on notebooks ASPM can provide significant
power-saving, therefore we want to give users the option to enable
ASPM. With the new sysfs attributes users can control which ASPM
link-states are disabled.

v2:
- use a dedicated sysfs attribute per link state
- allow separate control of ASPM and PCI PM L1 sub-states

v3:
- patch 3: statically allocate the attribute group
- patch 3: replace snprintf with printf
- add patch 4

Heiner Kallweit (4):
  PCI/ASPM: add L1 sub-state support to pci_disable_link_state
  PCI/ASPM: allow to re-enable Clock PM
  PCI/ASPM: add sysfs attributes for controlling ASPM
  PCI/ASPM: remove Kconfig option PCIEASPM_DEBUG and related code

 Documentation/ABI/testing/sysfs-bus-pci |  13 +
 drivers/pci/pci-sysfs.c                 |   6 +-
 drivers/pci/pci.h                       |  12 +-
 drivers/pci/pcie/Kconfig                |   7 -
 drivers/pci/pcie/aspm.c                 | 300 ++++++++++++++++++------
 include/linux/pci-aspm.h                |  10 +-
 6 files changed, 254 insertions(+), 94 deletions(-)

-- 
2.23.0

[PATCH v3 1/4] PCI/ASPM: add L1 sub-state support to pci_disable_link_state

[Heiner Kallweit]

Add support for disabling states L1.1 and L1.2 to
pci_disable_link_state. Allow separate control of
ASPM and PCI PM L1 sub-states.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
v2:
- allow separate control of ASPM and PCI PM L1 sub-states
---
 drivers/pci/pcie/aspm.c  | 11 ++++++++++-
 include/linux/pci-aspm.h | 10 +++++++---
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 464f8f926..1c1b9b7d6 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -1095,7 +1095,16 @@ static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem)
 	if (state & PCIE_LINK_STATE_L0S)
 		link->aspm_disable |= ASPM_STATE_L0S;
 	if (state & PCIE_LINK_STATE_L1)
-		link->aspm_disable |= ASPM_STATE_L1;
+		/* sub-states require L1 */
+		link->aspm_disable |= ASPM_STATE_L1 | ASPM_STATE_L1SS;
+	if (state & PCIE_LINK_STATE_L1_1)
+		link->aspm_disable |= ASPM_STATE_L1_1;
+	if (state & PCIE_LINK_STATE_L1_2)
+		link->aspm_disable |= ASPM_STATE_L1_2;
+	if (state & PCIE_LINK_STATE_L1_1_PCIPM)
+		link->aspm_disable |= ASPM_STATE_L1_1_PCIPM;
+	if (state & PCIE_LINK_STATE_L1_2_PCIPM)
+		link->aspm_disable |= ASPM_STATE_L1_2_PCIPM;
 	pcie_config_aspm_link(link, policy_to_aspm_state(link));
 
 	if (state & PCIE_LINK_STATE_CLKPM) {
diff --git a/include/linux/pci-aspm.h b/include/linux/pci-aspm.h
index 67064145d..f635cbdff 100644
--- a/include/linux/pci-aspm.h
+++ b/include/linux/pci-aspm.h
@@ -19,9 +19,13 @@
 
 #include <linux/pci.h>
 
-#define PCIE_LINK_STATE_L0S	1
-#define PCIE_LINK_STATE_L1	2
-#define PCIE_LINK_STATE_CLKPM	4
+#define PCIE_LINK_STATE_L0S		BIT(0)
+#define PCIE_LINK_STATE_L1		BIT(1)
+#define PCIE_LINK_STATE_CLKPM		BIT(2)
+#define PCIE_LINK_STATE_L1_1		BIT(3)
+#define PCIE_LINK_STATE_L1_2		BIT(4)
+#define PCIE_LINK_STATE_L1_1_PCIPM	BIT(5)
+#define PCIE_LINK_STATE_L1_2_PCIPM	BIT(6)
 
 #ifdef CONFIG_PCIEASPM
 int pci_disable_link_state(struct pci_dev *pdev, int state);
-- 
2.23.0

[PATCH v3 2/4] PCI/ASPM: allow to re-enable Clock PM

[Heiner Kallweit]

So far Clock PM can't be re-enabled once it has been disabled with
a call to pci_disable_link_state(). Reason is that clkpm_capable
is reset. Change this by adding a clkpm_disable field similar to
aspm_disable.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/pci/pcie/aspm.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 1c1b9b7d6..149b876c9 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -65,6 +65,7 @@ struct pcie_link_state {
 	u32 clkpm_capable:1;		/* Clock PM capable? */
 	u32 clkpm_enabled:1;		/* Current Clock PM state */
 	u32 clkpm_default:1;		/* Default Clock PM state by BIOS */
+	u32 clkpm_disable:1;		/* Clock PM disabled */
 
 	/* Exit latencies */
 	struct aspm_latency latency_up;	/* Upstream direction exit latency */
@@ -162,8 +163,11 @@ static void pcie_set_clkpm_nocheck(struct pcie_link_state *link, int enable)
 
 static void pcie_set_clkpm(struct pcie_link_state *link, int enable)
 {
-	/* Don't enable Clock PM if the link is not Clock PM capable */
-	if (!link->clkpm_capable)
+	/*
+	 * Don't enable Clock PM if the link is not Clock PM capable
+	 * or Clock PM is disabled
+	 */
+	if (!link->clkpm_capable || link->clkpm_disable)
 		enable = 0;
 	/* Need nothing if the specified equals to current state */
 	if (link->clkpm_enabled == enable)
@@ -193,7 +197,8 @@ static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist)
 	}
 	link->clkpm_enabled = enabled;
 	link->clkpm_default = enabled;
-	link->clkpm_capable = (blacklist) ? 0 : capable;
+	link->clkpm_capable = capable;
+	link->clkpm_disable = blacklist ? 1 : 0;
 }
 
 static bool pcie_retrain_link(struct pcie_link_state *link)
@@ -1107,10 +1112,9 @@ static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem)
 		link->aspm_disable |= ASPM_STATE_L1_2_PCIPM;
 	pcie_config_aspm_link(link, policy_to_aspm_state(link));
 
-	if (state & PCIE_LINK_STATE_CLKPM) {
-		link->clkpm_capable = 0;
-		pcie_set_clkpm(link, 0);
-	}
+	if (state & PCIE_LINK_STATE_CLKPM)
+		link->clkpm_disable = 1;
+	pcie_set_clkpm(link, policy_to_clkpm_state(link));
 	mutex_unlock(&aspm_lock);
 	if (sem)
 		up_read(&pci_bus_sem);
-- 
2.23.0

[PATCH v3 3/4] PCI/ASPM: add sysfs attributes for controlling ASPM

[Heiner Kallweit]

Background of this extension is a problem with the r8169 network driver.
Several combinations of board chipsets and network chip versions have
problems if ASPM is enabled, therefore we have to disable ASPM per default.
However especially on notebooks ASPM can provide significant power-saving,
therefore we want to give users the option to enable ASPM. With the new sysfs
attributes users can control which ASPM link-states are enabled/disabled.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
v2:
- use a dedicated sysfs attribute per link state
- allow separate control of ASPM and PCI PM L1 sub-states
v3:
- statically allocate the attribute group
- replace snprintf with printf
- base on top of "PCI: Make pcie_downstream_port() available outside of access.c"
---
 Documentation/ABI/testing/sysfs-bus-pci |  13 ++
 drivers/pci/pci-sysfs.c                 |   3 +
 drivers/pci/pci.h                       |   4 +
 drivers/pci/pcie/aspm.c                 | 246 ++++++++++++++++++++++++
 4 files changed, 266 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 8bfee557e..49249a165 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -347,3 +347,16 @@ Description:
 		If the device has any Peer-to-Peer memory registered, this
 	        file contains a '1' if the memory has been published for
 		use outside the driver that owns the device.
+
+What		/sys/bus/pci/devices/.../aspm/aspm_l0s
+What		/sys/bus/pci/devices/.../aspm/aspm_l1
+What		/sys/bus/pci/devices/.../aspm/aspm_l1_1
+What		/sys/bus/pci/devices/.../aspm/aspm_l1_2
+What		/sys/bus/pci/devices/.../aspm/aspm_l1_1_pcipm
+What		/sys/bus/pci/devices/.../aspm/aspm_l1_2_pcipm
+What		/sys/bus/pci/devices/.../aspm/aspm_clkpm
+date:		August 2019
+Contact:	Heiner Kallweit <hkallweit1@gmail.com>
+Description:	If ASPM is supported for an endpoint, then these files
+		can be used to disable or enable the individual
+		power management states.
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 793412954..0e76c02e0 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1587,6 +1587,9 @@ static const struct attribute_group *pci_dev_attr_groups[] = {
 	&pcie_dev_attr_group,
 #ifdef CONFIG_PCIEAER
 	&aer_stats_attr_group,
+#endif
+#ifdef CONFIG_PCIEASPM
+	&aspm_ctrl_attr_group,
 #endif
 	NULL,
 };
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 85e9fc14e..3908fb23d 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -649,4 +649,8 @@ static inline void pci_aer_clear_fatal_status(struct pci_dev *dev) { }
 static inline void pci_aer_clear_device_status(struct pci_dev *dev) { }
 #endif
 
+#ifdef CONFIG_PCIEASPM
+extern const struct attribute_group aspm_ctrl_attr_group;
+#endif
+
 #endif /* DRIVERS_PCI_H */
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 149b876c9..0d54cd7c7 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -1308,6 +1308,252 @@ void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev)
 }
 #endif
 
+static struct pcie_link_state *aspm_get_parent_link(struct pci_dev *pdev)
+{
+	struct pci_dev *parent = pdev->bus->self;
+
+	if (pcie_downstream_port(pdev))
+		parent = pdev;
+
+	return parent ? parent->link_state : NULL;
+}
+
+static bool pcie_check_valid_aspm_endpoint(struct pci_dev *pdev)
+{
+	struct pcie_link_state *link;
+
+	if (!pci_is_pcie(pdev) || pci_pcie_type(pdev) != PCI_EXP_TYPE_ENDPOINT)
+		return false;
+
+	link = aspm_get_parent_link(pdev);
+
+	return link && link->aspm_capable;
+}
+
+static ssize_t aspm_attr_show_common(struct device *dev,
+				     struct device_attribute *attr,
+				     char *buf, int state)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct pcie_link_state *link;
+	int val;
+
+	link = aspm_get_parent_link(pdev);
+	if (!link)
+		return -EOPNOTSUPP;
+
+	mutex_lock(&aspm_lock);
+	val = !!(link->aspm_enabled & state);
+	mutex_unlock(&aspm_lock);
+
+	return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t aspm_l0s_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	return aspm_attr_show_common(dev, attr, buf, ASPM_STATE_L0S);
+}
+
+static ssize_t aspm_l1_show(struct device *dev,
+			    struct device_attribute *attr, char *buf)
+{
+	return aspm_attr_show_common(dev, attr, buf, ASPM_STATE_L1);
+}
+
+static ssize_t aspm_l1_1_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	return aspm_attr_show_common(dev, attr, buf, ASPM_STATE_L1_1);
+}
+
+static ssize_t aspm_l1_2_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	return aspm_attr_show_common(dev, attr, buf, ASPM_STATE_L1_2);
+}
+
+static ssize_t aspm_l1_1_pcipm_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	return aspm_attr_show_common(dev, attr, buf, ASPM_STATE_L1_1_PCIPM);
+}
+
+static ssize_t aspm_l1_2_pcipm_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	return aspm_attr_show_common(dev, attr, buf, ASPM_STATE_L1_2_PCIPM);
+}
+
+static ssize_t aspm_attr_store_common(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t len, int state)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct pcie_link_state *link;
+	bool state_enable;
+
+	if (aspm_disabled)
+		return -EPERM;
+
+	link = aspm_get_parent_link(pdev);
+	if (!link)
+		return -EOPNOTSUPP;
+
+	if (!(link->aspm_capable & state))
+		return -EOPNOTSUPP;
+
+	if (strtobool(buf, &state_enable) < 0)
+		return -EINVAL;
+
+	down_read(&pci_bus_sem);
+	mutex_lock(&aspm_lock);
+
+	if (state_enable)
+		link->aspm_disable &= ~state;
+	else
+		link->aspm_disable |= state;
+
+	if (link->aspm_disable & ASPM_STATE_L1)
+		link->aspm_disable |= ASPM_STATE_L1SS;
+
+	pcie_config_aspm_link(link, policy_to_aspm_state(link));
+
+	mutex_unlock(&aspm_lock);
+	up_read(&pci_bus_sem);
+
+	return len;
+}
+
+static ssize_t aspm_l0s_store(struct device *dev,
+			      struct device_attribute *attr,
+			      const char *buf, size_t len)
+{
+	return aspm_attr_store_common(dev, attr, buf, len, ASPM_STATE_L0S);
+}
+
+static ssize_t aspm_l1_store(struct device *dev,
+			     struct device_attribute *attr,
+			     const char *buf, size_t len)
+{
+	return aspm_attr_store_common(dev, attr, buf, len, ASPM_STATE_L1);
+}
+
+static ssize_t aspm_l1_1_store(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t len)
+{
+	return aspm_attr_store_common(dev, attr, buf, len, ASPM_STATE_L1_1);
+}
+
+static ssize_t aspm_l1_2_store(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t len)
+{
+	return aspm_attr_store_common(dev, attr, buf, len, ASPM_STATE_L1_2);
+}
+
+static ssize_t aspm_l1_1_pcipm_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t len)
+{
+	return aspm_attr_store_common(dev, attr, buf, len,
+				      ASPM_STATE_L1_1_PCIPM);
+}
+
+static ssize_t aspm_l1_2_pcipm_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t len)
+{
+	return aspm_attr_store_common(dev, attr, buf, len,
+				      ASPM_STATE_L1_2_PCIPM);
+}
+
+static ssize_t aspm_clkpm_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct pcie_link_state *link;
+	int val;
+
+	link = aspm_get_parent_link(pdev);
+	if (!link)
+		return -EOPNOTSUPP;
+
+	mutex_lock(&aspm_lock);
+	val = link->clkpm_enabled;
+	mutex_unlock(&aspm_lock);
+
+	return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t aspm_clkpm_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t len)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct pcie_link_state *link;
+	bool state_enable;
+
+	if (aspm_disabled)
+		return -EPERM;
+
+	link = aspm_get_parent_link(pdev);
+	if (!link)
+		return -EOPNOTSUPP;
+
+	if (!link->clkpm_capable)
+		return -EOPNOTSUPP;
+
+	if (strtobool(buf, &state_enable) < 0)
+		return -EINVAL;
+
+	down_read(&pci_bus_sem);
+	mutex_lock(&aspm_lock);
+
+	link->clkpm_disable = !state_enable;
+	pcie_set_clkpm(link, policy_to_clkpm_state(link));
+
+	mutex_unlock(&aspm_lock);
+	up_read(&pci_bus_sem);
+
+	return len;
+}
+
+static DEVICE_ATTR_RW(aspm_l0s);
+static DEVICE_ATTR_RW(aspm_l1);
+static DEVICE_ATTR_RW(aspm_l1_1);
+static DEVICE_ATTR_RW(aspm_l1_2);
+static DEVICE_ATTR_RW(aspm_l1_1_pcipm);
+static DEVICE_ATTR_RW(aspm_l1_2_pcipm);
+static DEVICE_ATTR_RW(aspm_clkpm);
+
+static struct attribute *aspm_ctrl_attrs[] = {
+	&dev_attr_aspm_l0s.attr,
+	&dev_attr_aspm_l1.attr,
+	&dev_attr_aspm_l1_1.attr,
+	&dev_attr_aspm_l1_2.attr,
+	&dev_attr_aspm_l1_1_pcipm.attr,
+	&dev_attr_aspm_l1_2_pcipm.attr,
+	&dev_attr_aspm_clkpm.attr,
+	NULL
+};
+
+static umode_t aspm_ctrl_attrs_are_visible(struct kobject *kobj,
+					   struct attribute *a, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	return pcie_check_valid_aspm_endpoint(pdev) ? a->mode : 0;
+}
+
+const struct attribute_group aspm_ctrl_attr_group = {
+	.name = "aspm",
+	.attrs = aspm_ctrl_attrs,
+	.is_visible = aspm_ctrl_attrs_are_visible,
+};
+
 static int __init pcie_aspm_disable(char *str)
 {
 	if (!strcmp(str, "off")) {
-- 
2.23.0

[PATCH v3 4/4] PCI/ASPM: remove Kconfig option PCIEASPM_DEBUG and related code

[Heiner Kallweit]

Now that we have sysfs attributes for enabling/disabling the individual
ASPM link states, this debug code isn't needed any longer.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/pci/pci-sysfs.c  |   3 --
 drivers/pci/pci.h        |   8 ---
 drivers/pci/pcie/Kconfig |   7 ---
 drivers/pci/pcie/aspm.c  | 105 ---------------------------------------
 4 files changed, 123 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 0e76c02e0..92bf1b1ce 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1330,7 +1330,6 @@ static int pci_create_capabilities_sysfs(struct pci_dev *dev)
 	int retval;
 
 	pcie_vpd_create_sysfs_dev_files(dev);
-	pcie_aspm_create_sysfs_dev_files(dev);
 
 	if (dev->reset_fn) {
 		retval = device_create_file(&dev->dev, &dev_attr_reset);
@@ -1340,7 +1339,6 @@ static int pci_create_capabilities_sysfs(struct pci_dev *dev)
 	return 0;
 
 error:
-	pcie_aspm_remove_sysfs_dev_files(dev);
 	pcie_vpd_remove_sysfs_dev_files(dev);
 	return retval;
 }
@@ -1416,7 +1414,6 @@ int __must_check pci_create_sysfs_dev_files(struct pci_dev *pdev)
 static void pci_remove_capabilities_sysfs(struct pci_dev *dev)
 {
 	pcie_vpd_remove_sysfs_dev_files(dev);
-	pcie_aspm_remove_sysfs_dev_files(dev);
 	if (dev->reset_fn) {
 		device_remove_file(&dev->dev, &dev_attr_reset);
 		dev->reset_fn = 0;
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 3908fb23d..9ede6a37a 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -532,14 +532,6 @@ static inline void pcie_aspm_pm_state_change(struct pci_dev *pdev) { }
 static inline void pcie_aspm_powersave_config_link(struct pci_dev *pdev) { }
 #endif
 
-#ifdef CONFIG_PCIEASPM_DEBUG
-void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev);
-void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev);
-#else
-static inline void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev) { }
-static inline void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev) { }
-#endif
-
 #ifdef CONFIG_PCIE_ECRC
 void pcie_set_ecrc_checking(struct pci_dev *dev);
 void pcie_ecrc_get_policy(char *str);
diff --git a/drivers/pci/pcie/Kconfig b/drivers/pci/pcie/Kconfig
index 362eb8cfa..a2e862d4e 100644
--- a/drivers/pci/pcie/Kconfig
+++ b/drivers/pci/pcie/Kconfig
@@ -79,13 +79,6 @@ config PCIEASPM
 
 	  When in doubt, say Y.
 
-config PCIEASPM_DEBUG
-	bool "Debug PCI Express ASPM"
-	depends on PCIEASPM
-	help
-	  This enables PCI Express ASPM debug support. It will add per-device
-	  interface to control ASPM.
-
 choice
 	prompt "Default ASPM policy"
 	default PCIEASPM_DEFAULT
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 0d54cd7c7..8c13a152f 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -1203,111 +1203,6 @@ bool pcie_aspm_enabled(struct pci_dev *pdev)
 }
 EXPORT_SYMBOL_GPL(pcie_aspm_enabled);
 
-#ifdef CONFIG_PCIEASPM_DEBUG
-static ssize_t link_state_show(struct device *dev,
-		struct device_attribute *attr,
-		char *buf)
-{
-	struct pci_dev *pci_device = to_pci_dev(dev);
-	struct pcie_link_state *link_state = pci_device->link_state;
-
-	return sprintf(buf, "%d\n", link_state->aspm_enabled);
-}
-
-static ssize_t link_state_store(struct device *dev,
-		struct device_attribute *attr,
-		const char *buf,
-		size_t n)
-{
-	struct pci_dev *pdev = to_pci_dev(dev);
-	struct pcie_link_state *link, *root = pdev->link_state->root;
-	u32 state;
-
-	if (aspm_disabled)
-		return -EPERM;
-
-	if (kstrtouint(buf, 10, &state))
-		return -EINVAL;
-	if ((state & ~ASPM_STATE_ALL) != 0)
-		return -EINVAL;
-
-	down_read(&pci_bus_sem);
-	mutex_lock(&aspm_lock);
-	list_for_each_entry(link, &link_list, sibling) {
-		if (link->root != root)
-			continue;
-		pcie_config_aspm_link(link, state);
-	}
-	mutex_unlock(&aspm_lock);
-	up_read(&pci_bus_sem);
-	return n;
-}
-
-static ssize_t clk_ctl_show(struct device *dev,
-		struct device_attribute *attr,
-		char *buf)
-{
-	struct pci_dev *pci_device = to_pci_dev(dev);
-	struct pcie_link_state *link_state = pci_device->link_state;
-
-	return sprintf(buf, "%d\n", link_state->clkpm_enabled);
-}
-
-static ssize_t clk_ctl_store(struct device *dev,
-		struct device_attribute *attr,
-		const char *buf,
-		size_t n)
-{
-	struct pci_dev *pdev = to_pci_dev(dev);
-	bool state;
-
-	if (strtobool(buf, &state))
-		return -EINVAL;
-
-	down_read(&pci_bus_sem);
-	mutex_lock(&aspm_lock);
-	pcie_set_clkpm_nocheck(pdev->link_state, state);
-	mutex_unlock(&aspm_lock);
-	up_read(&pci_bus_sem);
-
-	return n;
-}
-
-static DEVICE_ATTR_RW(link_state);
-static DEVICE_ATTR_RW(clk_ctl);
-
-static char power_group[] = "power";
-void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev)
-{
-	struct pcie_link_state *link_state = pdev->link_state;
-
-	if (!link_state)
-		return;
-
-	if (link_state->aspm_support)
-		sysfs_add_file_to_group(&pdev->dev.kobj,
-			&dev_attr_link_state.attr, power_group);
-	if (link_state->clkpm_capable)
-		sysfs_add_file_to_group(&pdev->dev.kobj,
-			&dev_attr_clk_ctl.attr, power_group);
-}
-
-void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev)
-{
-	struct pcie_link_state *link_state = pdev->link_state;
-
-	if (!link_state)
-		return;
-
-	if (link_state->aspm_support)
-		sysfs_remove_file_from_group(&pdev->dev.kobj,
-			&dev_attr_link_state.attr, power_group);
-	if (link_state->clkpm_capable)
-		sysfs_remove_file_from_group(&pdev->dev.kobj,
-			&dev_attr_clk_ctl.attr, power_group);
-}
-#endif
-
 static struct pcie_link_state *aspm_get_parent_link(struct pci_dev *pdev)
 {
 	struct pci_dev *parent = pdev->bus->self;
-- 
2.23.0

Re: [PATCH v3 0/4] PCI/ASPM: add sysfs attributes for controlling ASPM

[Heiner Kallweit]

On 23.08.2019 08:11, Heiner Kallweit wrote:
> Background of this extension is a problem with the r8169 network driver.
> Several combinations of board chipsets and network chip versions have
> problems if ASPM is enabled, therefore we have to disable ASPM per
> default. However especially on notebooks ASPM can provide significant
> power-saving, therefore we want to give users the option to enable
> ASPM. With the new sysfs attributes users can control which ASPM
> link-states are disabled.
> 
> v2:
> - use a dedicated sysfs attribute per link state
> - allow separate control of ASPM and PCI PM L1 sub-states
> 
> v3:
> - patch 3: statically allocate the attribute group
> - patch 3: replace snprintf with printf
> - add patch 4
> 
> Heiner Kallweit (4):
>   PCI/ASPM: add L1 sub-state support to pci_disable_link_state
>   PCI/ASPM: allow to re-enable Clock PM
>   PCI/ASPM: add sysfs attributes for controlling ASPM
>   PCI/ASPM: remove Kconfig option PCIEASPM_DEBUG and related code
> 
>  Documentation/ABI/testing/sysfs-bus-pci |  13 +
>  drivers/pci/pci-sysfs.c                 |   6 +-
>  drivers/pci/pci.h                       |  12 +-
>  drivers/pci/pcie/Kconfig                |   7 -
>  drivers/pci/pcie/aspm.c                 | 300 ++++++++++++++++++------
>  include/linux/pci-aspm.h                |  10 +-
>  6 files changed, 254 insertions(+), 94 deletions(-)
> 
Found a functional error during more testing. Will submit a v4 once fixed.
Please disregard this series.