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From: Heiner Kallweit <hkallweit1@gmail.com>
To: Frederick Lawler <fred@fredlawl.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Greg KH <gregkh@linuxfoundation.org>,
	Rajat Jain <rajatja@google.com>
Cc: "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>
Subject: [PATCH v2 2/3] PCI/ASPM: allow to re-enable Clock PM
Date: Wed, 21 Aug 2019 20:17:43 +0200
Message-ID: <d100911d-9cb1-e970-1f99-323d70ccdb7f@gmail.com> (raw)
In-Reply-To: <b4b1518a-d0e8-9534-5211-115107e770e1@gmail.com>

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



  parent reply index

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-21 18:14 [PATCH v2 0/3] PCI/ASPM: add sysfs attributes for controlling ASPM Heiner Kallweit
2019-08-21 18:17 ` [PATCH v2 1/3] PCI/ASPM: add L1 sub-state support to pci_disable_link_state Heiner Kallweit
2019-08-21 18:17 ` Heiner Kallweit [this message]
2019-08-21 18:18 ` [PATCH v2 3/3] PCI/ASPM: add sysfs attributes for controlling ASPM Heiner Kallweit
2019-08-22 13:05   ` Greg KH
2019-08-22 19:15     ` Heiner Kallweit
2019-08-22 19:46       ` Heiner Kallweit

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