This is a note to let you know that I've just added the patch titled
PCI/ASPM: Fix L1 substate handling in aspm_attr_store_common()
to the 6.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-aspm-fix-l1-substate-handling-in-aspm_attr_store_common.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 8e37372ad0bea4c9b4712d9943f6ae96cff9491f Mon Sep 17 00:00:00 2001
From: Heiner Kallweit <hkallweit1@xxxxxxxxx>
Date: Wed, 11 Oct 2023 09:46:45 +0200
Subject: PCI/ASPM: Fix L1 substate handling in aspm_attr_store_common()
From: Heiner Kallweit <hkallweit1@xxxxxxxxx>
commit 8e37372ad0bea4c9b4712d9943f6ae96cff9491f upstream.
aspm_attr_store_common(), which handles sysfs control of ASPM, has the same
problem as fb097dcd5a28 ("PCI/ASPM: Disable only ASPM_STATE_L1 when driver
disables L1"): disabling L1 adds only ASPM_L1 (but not any of the L1.x
substates) to the "aspm_disable" mask.
Enabling one substate, e.g., L1.1, via sysfs removes ASPM_L1 from the
disable mask. Since disabling L1 via sysfs doesn't add any of the
substates to the disable mask, enabling L1.1 actually enables *all* the
substates.
In this scenario:
- Write 0 to "l1_aspm" to disable L1
- Write 1 to "l1_1_aspm" to enable L1.1
the intention is to disable L1 and all L1.x substates, then enable just
L1.1, but in fact, *all* L1.x substates are enabled.
Fix this by explicitly disabling all the L1.x substates when disabling L1.
Fixes: 72ea91afbfb0 ("PCI/ASPM: Add sysfs attributes for controlling ASPM link states")
Link: https://lore.kernel.org/r/6ba7dd79-9cfe-4ed0-a002-d99cb842f361@xxxxxxxxx
Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pci/pcie/aspm.c | 2 ++
1 file changed, 2 insertions(+)
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -1248,6 +1248,8 @@ static ssize_t aspm_attr_store_common(st
link->aspm_disable &= ~ASPM_STATE_L1;
} else {
link->aspm_disable |= state;
+ if (state & ASPM_STATE_L1)
+ link->aspm_disable |= ASPM_STATE_L1SS;
}
pcie_config_aspm_link(link, policy_to_aspm_state(link));
Patches currently in stable-queue which might be from hkallweit1@xxxxxxxxx are
queue-6.5/pci-aspm-fix-l1-substate-handling-in-aspm_attr_store_common.patch
