6.6-stable review patch. If anyone has any objections, please let me know.
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From: Heiner Kallweit hkallweit1@gmail.com
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@gmail.com Signed-off-by: Heiner Kallweit hkallweit1@gmail.com [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas bhelgaas@google.com Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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));