[PATCH 4.19 55/71] PCI/ASPM: Disable only ASPM_STATE_L1 when driver disables L1

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ajay Agarwal <ajayagarwal@google.com>

[ Upstream commit fb097dcd5a28c0a2325632405c76a66777a6bed9 ]

Previously pci_disable_link_state(PCIE_LINK_STATE_L1) disabled L1SS as well
as L1.  This is unnecessary since pcie_config_aspm_link() takes care that
L1SS is not enabled if L1 is disabled.

Disable only ASPM_STATE_L1 when the caller disables L1.  No functional
changes intended.

This is consistent with aspm_attr_store_common(), which disables only L1,
not L1SS, when L1 is disabled via the sysfs "l1_aspm" file.

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20230504111301.229358-2-ajayagarwal@google.com
Signed-off-by: Ajay Agarwal <ajayagarwal@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Stable-dep-of: 3cb4f534bac0 ("Revert "PCI/ASPM: Disable only ASPM_STATE_L1 when driver, disables L1"")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pci/pcie/aspm.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 8f934c88dcd76..8db6a9084a12a 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -1110,8 +1110,7 @@ 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)
-		/* L1 PM substates require L1 */
-		link->aspm_disable |= ASPM_STATE_L1 | ASPM_STATE_L1SS;
+		link->aspm_disable |= ASPM_STATE_L1;
 	if (state & PCIE_LINK_STATE_L1_1)
 		link->aspm_disable |= ASPM_STATE_L1_1;
 	if (state & PCIE_LINK_STATE_L1_2)
-- 
2.42.0