From 70b70a4307cccebe91388337b1c85735ce4de6ff Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Mon, 18 Sep 2023 14:48:01 +0200 Subject: [PATCH 1/2] PCI/sysfs: Protect driver's D3cold preference from user space struct pci_dev contains two flags which govern whether the device may suspend to D3cold: * no_d3cold provides an opt-out for drivers (e.g. if a device is known to not wake from D3cold) * d3cold_allowed provides an opt-out for user space (default is true, user space may set to false) Since commit 9d26d3a8f1b0 ("PCI: Put PCIe ports into D3 during suspend"), the user space setting overwrites the driver setting. Essentially user space is trusted to know better than the driver whether D3cold is working. That feels unsafe and wrong. Assume that the change was introduced inadvertently and do not overwrite no_d3cold when d3cold_allowed is modified. Instead, consider d3cold_allowed in addition to no_d3cold when choosing a suspend state for the device. That way, user space may opt out of D3cold if the driver hasn't, but it may no longer force an opt in if the driver has opted out. Fixes: 9d26d3a8f1b0 ("PCI: Put PCIe ports into D3 during suspend") Link: https://lore.kernel.org/r/b8a7f4af2b73f6b506ad8ddee59d747cbf834606.1695025365.git.lukas@wunner.de Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Reviewed-by: Mika Westerberg Reviewed-by: Mario Limonciello Cc: stable@vger.kernel.org # v4.8+ --- drivers/pci/pci-acpi.c | 2 +- drivers/pci/pci-sysfs.c | 5 +---- 2 files changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index a05350a4e49c..05b7357bd258 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -911,7 +911,7 @@ pci_power_t acpi_pci_choose_state(struct pci_dev *pdev) { int acpi_state, d_max; - if (pdev->no_d3cold) + if (pdev->no_d3cold || !pdev->d3cold_allowed) d_max = ACPI_STATE_D3_HOT; else d_max = ACPI_STATE_D3_COLD; diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index d9eede2dbc0e..5e741a05cf2c 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -530,10 +530,7 @@ static ssize_t d3cold_allowed_store(struct device *dev, return -EINVAL; pdev->d3cold_allowed = !!val; - if (pdev->d3cold_allowed) - pci_d3cold_enable(pdev); - else - pci_d3cold_disable(pdev); + pci_bridge_d3_update(pdev); pm_runtime_resume(dev); From 7d08f21f8c6307cb05cabb8d86e90ff6ccba57e9 Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Wed, 4 Oct 2023 09:49:59 -0500 Subject: [PATCH 2/2] x86/PCI: Avoid PME from D3hot/D3cold for AMD Rembrandt and Phoenix USB4 Iain reports that USB devices can't be used to wake a Lenovo Z13 from suspend. This occurs because on some AMD platforms, even though the Root Ports advertise PME_Support for D3hot and D3cold, wakeup events from devices on a USB4 controller don't result in wakeup interrupts from the Root Port when amd-pmc has put the platform in a hardware sleep state. If amd-pmc will be involved in the suspend, remove D3hot and D3cold from the PME_Support mask of Root Ports above USB4 controllers so we avoid those states if we need wakeups. Restore D3 support at resume so that it can be used by runtime suspend. This affects both AMD Rembrandt and Phoenix SoCs. "pm_suspend_target_state == PM_SUSPEND_ON" means we're doing runtime suspend, and amd-pmc will not be involved. In that case PMEs work as advertised in D3hot/D3cold, so we don't need to do anything. Note that amd-pmc is technically optional, and there's no need for this quirk if it's not present, but we assume it's always present because power consumption is so high without it. Fixes: 9d26d3a8f1b0 ("PCI: Put PCIe ports into D3 during suspend") Link: https://lore.kernel.org/r/20231004144959.158840-1-mario.limonciello@amd.com Reported-by: Iain Lane Closes: https://forums.lenovo.com/t5/Ubuntu/Z13-can-t-resume-from-suspend-with-external-USB-keyboard/m-p/5217121 Signed-off-by: Mario Limonciello [bhelgaas: commit log, move to arch/x86/pci/fixup.c, add #includes] Signed-off-by: Bjorn Helgaas Cc: stable@vger.kernel.org --- arch/x86/pci/fixup.c | 59 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c index e3ec02e6ac9f..f347c20247d3 100644 --- a/arch/x86/pci/fixup.c +++ b/arch/x86/pci/fixup.c @@ -3,9 +3,11 @@ * Exceptions for specific devices. Usually work-arounds for fatal design flaws. */ +#include #include #include #include +#include #include #include #include @@ -904,3 +906,60 @@ static void chromeos_fixup_apl_pci_l1ss_capability(struct pci_dev *dev) } DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x5ad6, chromeos_save_apl_pci_l1ss_capability); DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_INTEL, 0x5ad6, chromeos_fixup_apl_pci_l1ss_capability); + +#ifdef CONFIG_SUSPEND +/* + * Root Ports on some AMD SoCs advertise PME_Support for D3hot and D3cold, but + * if the SoC is put into a hardware sleep state by the amd-pmc driver, the + * Root Ports don't generate wakeup interrupts for USB devices. + * + * When suspending, remove D3hot and D3cold from the PME_Support advertised + * by the Root Port so we don't use those states if we're expecting wakeup + * interrupts. Restore the advertised PME_Support when resuming. + */ +static void amd_rp_pme_suspend(struct pci_dev *dev) +{ + struct pci_dev *rp; + + /* + * PM_SUSPEND_ON means we're doing runtime suspend, which means + * amd-pmc will not be involved so PMEs during D3 work as advertised. + * + * The PMEs *do* work if amd-pmc doesn't put the SoC in the hardware + * sleep state, but we assume amd-pmc is always present. + */ + if (pm_suspend_target_state == PM_SUSPEND_ON) + return; + + rp = pcie_find_root_port(dev); + if (!rp->pm_cap) + return; + + rp->pme_support &= ~((PCI_PM_CAP_PME_D3hot|PCI_PM_CAP_PME_D3cold) >> + PCI_PM_CAP_PME_SHIFT); + dev_info_once(&rp->dev, "quirk: disabling D3cold for suspend\n"); +} + +static void amd_rp_pme_resume(struct pci_dev *dev) +{ + struct pci_dev *rp; + u16 pmc; + + rp = pcie_find_root_port(dev); + if (!rp->pm_cap) + return; + + pci_read_config_word(rp, rp->pm_cap + PCI_PM_PMC, &pmc); + rp->pme_support = FIELD_GET(PCI_PM_CAP_PME_MASK, pmc); +} +/* Rembrandt (yellow_carp) */ +DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_AMD, 0x162e, amd_rp_pme_suspend); +DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_AMD, 0x162e, amd_rp_pme_resume); +DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_AMD, 0x162f, amd_rp_pme_suspend); +DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_AMD, 0x162f, amd_rp_pme_resume); +/* Phoenix (pink_sardine) */ +DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_AMD, 0x1668, amd_rp_pme_suspend); +DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_AMD, 0x1668, amd_rp_pme_resume); +DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_AMD, 0x1669, amd_rp_pme_suspend); +DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_AMD, 0x1669, amd_rp_pme_resume); +#endif /* CONFIG_SUSPEND */