Bjorn / Lorenzo,
Could you please review this change?
Thanks,
Vidya Sagar
On 10/25/2020 12:34 AM, Vidya Sagar wrote:
Previously ASPM L1-Sub-States control registers (CTL1 and CTL2) weren't
saved and restored during suspend/resume leading to ASPM-L1SS
configuration being lost post resume.
Save the ASPM-L1SS control registers so that the configuration is retained
post resume.
Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
---
v1:
* It would be really good if someone can verify it on a non tegra194 platform
drivers/pci/pci.c | 7 +++++++
drivers/pci/pci.h | 4 ++++
drivers/pci/pcie/aspm.c | 41 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 52 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index a458c46d7e39..034497264bde 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1551,6 +1551,7 @@ 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);
return pci_save_vc_state(dev);
@@ -1656,6 +1657,7 @@ void pci_restore_state(struct pci_dev *dev)
* 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);
@@ -3319,6 +3321,11 @@ void pci_allocate_cap_save_buffers(struct pci_dev *dev)
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);
}
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index fa12f7cbc1a0..8d2135f61e36 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -565,11 +565,15 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev);
void pcie_aspm_exit_link_state(struct pci_dev *pdev);
void pcie_aspm_pm_state_change(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_pm_state_change(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
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 253c30cc1967..d965bbc563ed 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -742,6 +742,47 @@ static void pcie_config_aspm_l1ss(struct pcie_link_state *link, u32 state)
PCI_L1SS_CTL1_L1SS_MASK, val);
}
+void pci_save_aspm_l1ss_state(struct pci_dev *dev)
+{
+ struct pci_cap_saved_state *save_state;
+ int aspm_l1ss;
+ u32 *cap;
+
+ if (!pci_is_pcie(dev))
+ return;
+
+ aspm_l1ss = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_L1SS);
+ if (!aspm_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, aspm_l1ss + PCI_L1SS_CTL1, cap++);
+ pci_read_config_dword(dev, aspm_l1ss + PCI_L1SS_CTL2, cap++);
+}
+
+void pci_restore_aspm_l1ss_state(struct pci_dev *dev)
+{
+ struct pci_cap_saved_state *save_state;
+ int aspm_l1ss;
+ u32 *cap;
+
+ if (!pci_is_pcie(dev))
+ return;
+
+ save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_L1SS);
+ aspm_l1ss = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_L1SS);
+ if (!save_state || !aspm_l1ss)
+ return;
+
+ cap = (u32 *)&save_state->cap.data[0];
+ pci_write_config_dword(dev, aspm_l1ss + PCI_L1SS_CTL1, *cap++);
+ pci_write_config_dword(dev, aspm_l1ss + PCI_L1SS_CTL2, *cap++);
+}
+
static void pcie_config_aspm_dev(struct pci_dev *pdev, u32 val)
{
pcie_capability_clear_and_set_word(pdev, PCI_EXP_LNKCTL,
