From: Bjorn Helgaas bhelgaas@google.com
commit a7152be79b627428c628da2a887ca4b2512a78fd upstream.
This reverts commit 4ff116d0d5fd8a025604b0802d93a2d5f4e465d1.
Tasev Nikola and Mark Enriquez reported that resume from suspend was broken in v6.1-rc1. Tasev bisected to a47126ec29f5 ("PCI/PTM: Cache PTM Capability offset"), but we can't figure out how that could be related.
Mark saw the same symptoms and bisected to 4ff116d0d5fd ("PCI/ASPM: Save L1 PM Substates Capability for suspend/resume"), which does have a connection: it restores L1 Substates configuration while ASPM L1 may be enabled:
pci_restore_state pci_restore_aspm_l1ss_state aspm_program_l1ss pci_write_config_dword(PCI_L1SS_CTL1, ctl1) # L1SS restore pci_restore_pcie_state pcie_capability_write_word(PCI_EXP_LNKCTL, cap[i++]) # L1 restore
which is a problem because PCIe r6.0, sec 5.5.4, requires that:
If setting either or both of the enable bits for ASPM L1 PM Substates, both ports must be configured as described in this section while ASPM L1 is disabled.
Separately, Thomas Witt reported that 5e85eba6f50d ("PCI/ASPM: Refactor L1 PM Substates Control Register programming") broke suspend/resume, and it depends on 4ff116d0d5fd.
Revert 4ff116d0d5fd ("PCI/ASPM: Save L1 PM Substates Capability for suspend/resume") to fix the resume issue and enable revert of 5e85eba6f50d to fix the issue Thomas reported.
Note that reverting 4ff116d0d5fd means L1 Substates config may be lost on suspend/resume. As far as we know the system will use more power but will still *work* correctly.
Fixes: 4ff116d0d5fd ("PCI/ASPM: Save L1 PM Substates Capability for suspend/resume") Link: https://bugzilla.kernel.org/show_bug.cgi?id=216782 Link: https://bugzilla.kernel.org/show_bug.cgi?id=216877 Reported-by: Tasev Nikola tasev.stefanoska@skynet.be Reported-by: Mark Enriquez enriquezmark36@gmail.com Reported-by: Thomas Witt kernel@witt.link Tested-by: Mark Enriquez enriquezmark36@gmail.com Tested-by: Thomas Witt kernel@witt.link Signed-off-by: Bjorn Helgaas bhelgaas@google.com Cc: stable@vger.kernel.org # v6.1+ Cc: Vidya Sagar vidyas@nvidia.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pci/pci.c | 7 ------- drivers/pci/pci.h | 4 ---- drivers/pci/pcie/aspm.c | 37 ------------------------------------- 3 files changed, 48 deletions(-)
--- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1665,7 +1665,6 @@ int pci_save_state(struct pci_dev *dev) return i;
pci_save_ltr_state(dev); - pci_save_aspm_l1ss_state(dev); pci_save_dpc_state(dev); pci_save_aer_state(dev); pci_save_ptm_state(dev); @@ -1772,7 +1771,6 @@ void pci_restore_state(struct pci_dev *d * LTR itself (in the PCIe capability). */ pci_restore_ltr_state(dev); - pci_restore_aspm_l1ss_state(dev);
pci_restore_pcie_state(dev); pci_restore_pasid_state(dev); @@ -3465,11 +3463,6 @@ void pci_allocate_cap_save_buffers(struc if (error) pci_err(dev, "unable to allocate suspend buffer for LTR\n");
- error = pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_L1SS, - 2 * sizeof(u32)); - if (error) - pci_err(dev, "unable to allocate suspend buffer for ASPM-L1SS\n"); - pci_allocate_vc_save_buffers(dev); }
--- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -565,14 +565,10 @@ bool pcie_wait_for_link(struct pci_dev * void pcie_aspm_init_link_state(struct pci_dev *pdev); void pcie_aspm_exit_link_state(struct pci_dev *pdev); void pcie_aspm_powersave_config_link(struct pci_dev *pdev); -void pci_save_aspm_l1ss_state(struct pci_dev *dev); -void pci_restore_aspm_l1ss_state(struct pci_dev *dev); #else static inline void pcie_aspm_init_link_state(struct pci_dev *pdev) { } static inline void pcie_aspm_exit_link_state(struct pci_dev *pdev) { } static inline void pcie_aspm_powersave_config_link(struct pci_dev *pdev) { } -static inline void pci_save_aspm_l1ss_state(struct pci_dev *dev) { } -static inline void pci_restore_aspm_l1ss_state(struct pci_dev *dev) { } #endif
#ifdef CONFIG_PCIE_ECRC --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -757,43 +757,6 @@ static void pcie_config_aspm_l1ss(struct PCI_L1SS_CTL1_L1SS_MASK, val); }
-void pci_save_aspm_l1ss_state(struct pci_dev *dev) -{ - struct pci_cap_saved_state *save_state; - u16 l1ss = dev->l1ss; - u32 *cap; - - if (!l1ss) - return; - - save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_L1SS); - if (!save_state) - return; - - cap = (u32 *)&save_state->cap.data[0]; - pci_read_config_dword(dev, l1ss + PCI_L1SS_CTL2, cap++); - pci_read_config_dword(dev, l1ss + PCI_L1SS_CTL1, cap++); -} - -void pci_restore_aspm_l1ss_state(struct pci_dev *dev) -{ - struct pci_cap_saved_state *save_state; - u32 *cap, ctl1, ctl2; - u16 l1ss = dev->l1ss; - - if (!l1ss) - return; - - save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_L1SS); - if (!save_state) - return; - - cap = (u32 *)&save_state->cap.data[0]; - ctl2 = *cap++; - ctl1 = *cap; - aspm_program_l1ss(dev, ctl1, ctl2); -} - static void pcie_config_aspm_dev(struct pci_dev *pdev, u32 val) { pcie_capability_clear_and_set_word(pdev, PCI_EXP_LNKCTL,