This is a note to let you know that I've just added the patch titled
Revert "PCI/ASPM: Refactor L1 PM Substates Control Register programming"
to the 6.1-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:
revert-pci-aspm-refactor-l1-pm-substates-control-register-programming.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ff209ecc376a2ea8dd106a1f594427a5d94b7dd3 Mon Sep 17 00:00:00 2001
From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Date: Fri, 3 Feb 2023 13:57:39 -0600
Subject: Revert "PCI/ASPM: Refactor L1 PM Substates Control Register programming"
From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
commit ff209ecc376a2ea8dd106a1f594427a5d94b7dd3 upstream.
This reverts commit 5e85eba6f50dc288c22083a7e213152bcc4b8208.
Thomas Witt reported that 5e85eba6f50d ("PCI/ASPM: Refactor L1 PM Substates
Control Register programming") broke suspend/resume on a Tuxedo
Infinitybook S 14 v5, which seems to use a Clevo L140CU Mainboard.
The main symptom is:
iwlwifi 0000:02:00.0: Unable to change power state from D3hot to D0, device inaccessible
nvme 0000:03:00.0: Unable to change power state from D3hot to D0, device inaccessible
and the machine is only partially usable after resume. It can't run dmesg
and can't do a clean reboot. This happens on every suspend/resume cycle.
Revert 5e85eba6f50d until we can figure out the root cause.
Fixes: 5e85eba6f50d ("PCI/ASPM: Refactor L1 PM Substates Control Register programming")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216877
Reported-by: Thomas Witt <kernel@xxxxxxxxx>
Tested-by: Thomas Witt <kernel@xxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v6.1+
Cc: Vidya Sagar <vidyas@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pci/pcie/aspm.c | 74 +++++++++++++++++++----------------------
1 file changed, 34 insertions(+), 40 deletions(-)
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 915cbd939dd9..4b4184563a92 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -470,31 +470,6 @@ static void pci_clear_and_set_dword(struct pci_dev *pdev, int pos,
pci_write_config_dword(pdev, pos, val);
}
-static void aspm_program_l1ss(struct pci_dev *dev, u32 ctl1, u32 ctl2)
-{
- u16 l1ss = dev->l1ss;
- u32 l1_2_enable;
-
- /*
- * Per PCIe r6.0, sec 5.5.4, T_POWER_ON in PCI_L1SS_CTL2 must be
- * programmed prior to setting the L1.2 enable bits in PCI_L1SS_CTL1.
- */
- pci_write_config_dword(dev, l1ss + PCI_L1SS_CTL2, ctl2);
-
- /*
- * In addition, Common_Mode_Restore_Time and LTR_L1.2_THRESHOLD in
- * PCI_L1SS_CTL1 must be programmed *before* setting the L1.2
- * enable bits, even though they're all in PCI_L1SS_CTL1.
- */
- l1_2_enable = ctl1 & PCI_L1SS_CTL1_L1_2_MASK;
- ctl1 &= ~PCI_L1SS_CTL1_L1_2_MASK;
-
- pci_write_config_dword(dev, l1ss + PCI_L1SS_CTL1, ctl1);
- if (l1_2_enable)
- pci_write_config_dword(dev, l1ss + PCI_L1SS_CTL1,
- ctl1 | l1_2_enable);
-}
-
/* Calculate L1.2 PM substate timing parameters */
static void aspm_calc_l1ss_info(struct pcie_link_state *link,
u32 parent_l1ss_cap, u32 child_l1ss_cap)
@@ -504,6 +479,7 @@ static void aspm_calc_l1ss_info(struct pcie_link_state *link,
u32 t_common_mode, t_power_on, l1_2_threshold, scale, value;
u32 ctl1 = 0, ctl2 = 0;
u32 pctl1, pctl2, cctl1, cctl2;
+ u32 pl1_2_enables, cl1_2_enables;
if (!(link->aspm_support & ASPM_STATE_L1_2_MASK))
return;
@@ -552,21 +528,39 @@ static void aspm_calc_l1ss_info(struct pcie_link_state *link,
ctl2 == pctl2 && ctl2 == cctl2)
return;
- pctl1 &= ~(PCI_L1SS_CTL1_CM_RESTORE_TIME |
- PCI_L1SS_CTL1_LTR_L12_TH_VALUE |
- PCI_L1SS_CTL1_LTR_L12_TH_SCALE);
- pctl1 |= (ctl1 & (PCI_L1SS_CTL1_CM_RESTORE_TIME |
- PCI_L1SS_CTL1_LTR_L12_TH_VALUE |
- PCI_L1SS_CTL1_LTR_L12_TH_SCALE));
- aspm_program_l1ss(parent, pctl1, ctl2);
-
- cctl1 &= ~(PCI_L1SS_CTL1_CM_RESTORE_TIME |
- PCI_L1SS_CTL1_LTR_L12_TH_VALUE |
- PCI_L1SS_CTL1_LTR_L12_TH_SCALE);
- cctl1 |= (ctl1 & (PCI_L1SS_CTL1_CM_RESTORE_TIME |
- PCI_L1SS_CTL1_LTR_L12_TH_VALUE |
- PCI_L1SS_CTL1_LTR_L12_TH_SCALE));
- aspm_program_l1ss(child, cctl1, ctl2);
+ /* Disable L1.2 while updating. See PCIe r5.0, sec 5.5.4, 7.8.3.3 */
+ pl1_2_enables = pctl1 & PCI_L1SS_CTL1_L1_2_MASK;
+ cl1_2_enables = cctl1 & PCI_L1SS_CTL1_L1_2_MASK;
+
+ if (pl1_2_enables || cl1_2_enables) {
+ pci_clear_and_set_dword(child, child->l1ss + PCI_L1SS_CTL1,
+ PCI_L1SS_CTL1_L1_2_MASK, 0);
+ pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
+ PCI_L1SS_CTL1_L1_2_MASK, 0);
+ }
+
+ /* Program T_POWER_ON times in both ports */
+ pci_write_config_dword(parent, parent->l1ss + PCI_L1SS_CTL2, ctl2);
+ pci_write_config_dword(child, child->l1ss + PCI_L1SS_CTL2, ctl2);
+
+ /* Program Common_Mode_Restore_Time in upstream device */
+ pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
+ PCI_L1SS_CTL1_CM_RESTORE_TIME, ctl1);
+
+ /* Program LTR_L1.2_THRESHOLD time in both ports */
+ pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
+ PCI_L1SS_CTL1_LTR_L12_TH_VALUE |
+ PCI_L1SS_CTL1_LTR_L12_TH_SCALE, ctl1);
+ pci_clear_and_set_dword(child, child->l1ss + PCI_L1SS_CTL1,
+ PCI_L1SS_CTL1_LTR_L12_TH_VALUE |
+ PCI_L1SS_CTL1_LTR_L12_TH_SCALE, ctl1);
+
+ if (pl1_2_enables || cl1_2_enables) {
+ pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1, 0,
+ pl1_2_enables);
+ pci_clear_and_set_dword(child, child->l1ss + PCI_L1SS_CTL1, 0,
+ cl1_2_enables);
+ }
}
static void aspm_l1ss_init(struct pcie_link_state *link)
--
2.39.1
Patches currently in stable-queue which might be from bhelgaas@xxxxxxxxxx are
queue-6.1/revert-pci-aspm-refactor-l1-pm-substates-control-register-programming.patch
queue-6.1/revert-pci-aspm-save-l1-pm-substates-capability-for-suspend-resume.patch
