If we use sysfs to disable L1 ASPM, then enable one L1 ASPM substate
again, all other substates will also be enabled too:
link# grep . *
clkpm:1
l0s_aspm:1
l1_1_aspm:1
l1_1_pcipm:1
l1_2_aspm:1
l1_2_pcipm:1
l1_aspm:1
link# echo 0 > l1_aspm
link# grep . *
clkpm:1
l0s_aspm:1
l1_1_aspm:0
l1_1_pcipm:0
l1_2_aspm:0
l1_2_pcipm:0
l1_aspm:0
link# echo 1 > l1_2_aspm
link# grep . *
clkpm:1
l0s_aspm:1
l1_1_aspm:1
l1_1_pcipm:1
l1_2_aspm:1
l1_2_pcipm:1
l1_aspm:1
This is because disabled ASPM states weren't saved, so enable any of the
substate will also enable others.
So store the disabled ASPM states for consistency.
Signed-off-by: Kai-Heng Feng <kai.heng.f...@canonical.com>
---
drivers/pci/pcie/aspm.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index ac0557a305af..2ea9fddadfad 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -658,6 +658,8 @@ static void pcie_aspm_cap_init(struct pcie_link_state
*link, int blacklist)
/* Setup initial capable state. Will be updated later */
link->aspm_capable = link->aspm_support;
+ link->aspm_disable = link->aspm_capable & ~link->aspm_default;
+
/* Get and check endpoint acceptable latencies */
list_for_each_entry(child, &linkbus->devices, bus_list) {
u32 reg32, encoding;
@@ -1226,11 +1228,15 @@ static ssize_t aspm_attr_store_common(struct device
*dev,
mutex_lock(&aspm_lock);
if (state_enable) {
- link->aspm_disable &= ~state;
/* need to enable L1 for substates */
if (state & ASPM_STATE_L1SS)
- link->aspm_disable &= ~ASPM_STATE_L1;
+ state |= ASPM_STATE_L1;
+
+ link->aspm_disable &= ~state;
} else {
+ if (state == ASPM_STATE_L1)
+ state |= ASPM_STATE_L1SS;
+
link->aspm_disable |= state;
}
--
2.29.2
