PCI/ASPM: Allow re-enabling Clock PM

[ Upstream commit 35efea32b26f9aacc99bf07e0d2cdfba2028b099 ]

Previously Clock PM could not be re-enabled after being disabled by
pci_disable_link_state() because clkpm_capable was reset.  Change this by
adding a clkpm_disable field similar to aspm_disable.

Link: https://lore.kernel.org/r/4e8a66db-7d53-4a66-c26c-f0037ffaa705@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 32c3433..5a1bbf2 100644 (file)
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -64,6 +64,7 @@ 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 */
@@ -161,8 +162,11 @@ 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)
@@ -192,7 +196,8 @@ 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)
@@ -1097,10 +1102,9 @@ static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem)
                link->aspm_disable |= ASPM_STATE_L1;
        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);