[PATCH 4.14 049/199] PCI/ASPM: Clear the correct bits when enabling L1 substates

From: Greg Kroah-Hartman
Date: Wed Apr 22 2020 - 06:10:13 EST


From: Yicong Yang <yangyicong@xxxxxxxxxxxxx>

commit 58a3862a10a317a81097ab0c78aecebabb1704f5 upstream.

In pcie_config_aspm_l1ss(), we cleared the wrong bits when enabling ASPM L1
Substates. Instead of the L1.x enable bits (PCI_L1SS_CTL1_L1SS_MASK, 0xf), we
cleared the Link Activation Interrupt Enable bit (PCI_L1SS_CAP_L1_PM_SS,
0x10).

Clear the L1.x enable bits before writing the new L1.x configuration.

[bhelgaas: changelog]
Fixes: aeda9adebab8 ("PCI/ASPM: Configure L1 substate settings")
Link: https://lore.kernel.org/r/1584093227-1292-1-git-send-email-yangyicong@xxxxxxxxxxxxx
Signed-off-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
CC: stable@xxxxxxxxxxxxxxx # v4.11+
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/pci/pcie/aspm.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -693,9 +693,9 @@ static void pcie_config_aspm_l1ss(struct

/* Enable what we need to enable */
pci_clear_and_set_dword(parent, up_cap_ptr + PCI_L1SS_CTL1,
- PCI_L1SS_CAP_L1_PM_SS, val);
+ PCI_L1SS_CTL1_L1SS_MASK, val);
pci_clear_and_set_dword(child, dw_cap_ptr + PCI_L1SS_CTL1,
- PCI_L1SS_CAP_L1_PM_SS, val);
+ PCI_L1SS_CTL1_L1SS_MASK, val);
}

static void pcie_config_aspm_dev(struct pci_dev *pdev, u32 val)