Since "PCI: Add runtime PM support for PCIe ports", the parent PCIe port can be runtime-suspended which disables power resources via ACPI. This is incompatible with DSM, resulting in a GPU device which is still in D3 and locks up the kernel on resume. Mirror the behavior of Windows 8 and newer[1] (as observed via an AMLi debugger trace) and stop using the DSM functions for D3cold when power resources are available on the parent PCIe port. [1]: https://msdn.microsoft.com/windows/hardware/drivers/bringup/firmware-requirements-for-d3cold Signed-off-by: Peter Wu <peter@xxxxxxxxxxxxx> --- drivers/gpu/drm/nouveau/nouveau_acpi.c | 34 ++++++++++++++++++++++++++++++---- 1 file changed, 30 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c index df9f73e..e469df7 100644 --- a/drivers/gpu/drm/nouveau/nouveau_acpi.c +++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c @@ -46,6 +46,7 @@ static struct nouveau_dsm_priv { bool dsm_detected; bool optimus_detected; bool optimus_flags_detected; + bool optimus_skip_dsm; acpi_handle dhandle; acpi_handle rom_handle; } nouveau_dsm_priv; @@ -212,8 +213,26 @@ static const struct vga_switcheroo_handler nouveau_dsm_handler = { .get_client_id = nouveau_dsm_get_client_id, }; +/* Firmware supporting Windows 8 or later do not use _DSM to put the device into + * D3cold, they instead rely on disabling power resources on the parent. */ +static bool nouveau_pr3_present(struct pci_dev *pdev) +{ + struct pci_dev *parent_pdev = pci_upstream_bridge(pdev); + struct acpi_device *ad; + + if (!parent_pdev) + return false; + + ad = ACPI_COMPANION(&parent_pdev->dev); + if (!ad) + return false; + + return ad->power.flags.power_resources; +} + static void nouveau_dsm_pci_probe(struct pci_dev *pdev, bool *has_mux, - bool *has_opt, bool *has_opt_flags) + bool *has_opt, bool *has_opt_flags, + bool *has_power_resources) { acpi_handle dhandle; bool supports_mux; @@ -238,6 +257,7 @@ static void nouveau_dsm_pci_probe(struct pci_dev *pdev, bool *has_mux, *has_mux = supports_mux; *has_opt = !!optimus_funcs; *has_opt_flags = optimus_funcs & (1 << NOUVEAU_DSM_OPTIMUS_FLAGS); + *has_power_resources = false; if (optimus_funcs) { uint32_t result; @@ -247,6 +267,8 @@ static void nouveau_dsm_pci_probe(struct pci_dev *pdev, bool *has_mux, (result & OPTIMUS_ENABLED) ? "enabled" : "disabled", (result & OPTIMUS_DYNAMIC_PWR_CAP) ? "dynamic power, " : "", (result & OPTIMUS_HDA_CODEC_MASK) ? "hda bios codec supported" : ""); + + *has_power_resources = nouveau_pr3_present(pdev); } } @@ -258,6 +280,7 @@ static bool nouveau_dsm_detect(void) bool has_mux = false; bool has_optimus = false; bool has_optimus_flags = false; + bool has_power_resources = false; int vga_count = 0; bool guid_valid; bool ret = false; @@ -273,14 +296,14 @@ static bool nouveau_dsm_detect(void) vga_count++; nouveau_dsm_pci_probe(pdev, &has_mux, &has_optimus, - &has_optimus_flags); + &has_optimus_flags, &has_power_resources); } while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_3D << 8, pdev)) != NULL) { vga_count++; nouveau_dsm_pci_probe(pdev, &has_mux, &has_optimus, - &has_optimus_flags); + &has_optimus_flags, &has_power_resources); } /* find the optimus DSM or the old v1 DSM */ @@ -289,8 +312,11 @@ static bool nouveau_dsm_detect(void) &buffer); printk(KERN_INFO "VGA switcheroo: detected Optimus DSM method %s handle\n", acpi_method_name); + if (has_power_resources) + pr_info("nouveau: detected PR support, will not use DSM\n"); nouveau_dsm_priv.optimus_detected = true; nouveau_dsm_priv.optimus_flags_detected = has_optimus_flags; + nouveau_dsm_priv.optimus_skip_dsm = has_power_resources; ret = true; } else if (vga_count == 2 && has_mux && guid_valid) { acpi_get_name(nouveau_dsm_priv.dhandle, ACPI_FULL_PATHNAME, @@ -320,7 +346,7 @@ void nouveau_register_dsm_handler(void) void nouveau_switcheroo_optimus_dsm(void) { u32 result = 0; - if (!nouveau_dsm_priv.optimus_detected) + if (!nouveau_dsm_priv.optimus_detected || nouveau_dsm_priv.optimus_skip_dsm) return; if (nouveau_dsm_priv.optimus_flags_detected) -- 2.8.2 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
