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Commit 692a17dc authored by Peter Wu's avatar Peter Wu Committed by Ben Skeggs
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drm/nouveau/acpi: fix lockup with PCIe runtime PM 

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 (on a Clevo P651RA, GTX965M).

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.

pci_d3cold_disable() is not used because on some machines, the old DSM
method is broken. On a Lenovo T440p (GT 730M) memory and disk corruption
would occur, but that is fixed with this patch[2].

 [1]: https://msdn.microsoft.com/windows/hardware/drivers/bringup/firmware-requirements-for-d3cold
 [2]: https://github.com/Bumblebee-Project/bbswitch/issues/78#issuecomment-223549072



 v2: simply check directly for _PR3. Added affected machines.
 v3: fixed block comment coding style.

Reviewed-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: default avatarPeter Wu <peter@lekensteyn.nl>
Acked-by: default avatarDave Airlie <airlied@redhat.com>
Signed-off-by: default avatarBen Skeggs <bskeggs@redhat.com>
parent cba97805

drivers/gpu/drm/nouveau/nouveau_acpi.c

+31 −4
Original line number Diff line number Diff line
@@ -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;
@@ -212,9 +213,28 @@ 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 *parent_adev;



	if (!parent_pdev)

		return false;



	parent_adev = ACPI_COMPANION(&parent_pdev->dev);

	if (!parent_adev)

		return false;



	return acpi_has_method(parent_adev->handle, "_PR3");

}



static void nouveau_dsm_pci_probe(struct pci_dev *pdev, acpi_handle *dhandle_out,

				  bool *has_mux, bool *has_opt,

				  bool *has_opt_flags)

				  bool *has_opt_flags, bool *has_pr3)

{

	acpi_handle dhandle;

	bool supports_mux;
@@ -239,6 +259,7 @@ static void nouveau_dsm_pci_probe(struct pci_dev *pdev, acpi_handle *dhandle_out 
	*has_mux = supports_mux;

	*has_opt = !!optimus_funcs;

	*has_opt_flags = optimus_funcs & (1 << NOUVEAU_DSM_OPTIMUS_FLAGS);

	*has_pr3 = false;



	if (optimus_funcs) {

		uint32_t result;
@@ -248,6 +269,8 @@ static void nouveau_dsm_pci_probe(struct pci_dev *pdev, acpi_handle *dhandle_out 
			 (result & OPTIMUS_ENABLED) ? "enabled" : "disabled",

			 (result & OPTIMUS_DYNAMIC_PWR_CAP) ? "dynamic power, " : "",

			 (result & OPTIMUS_HDA_CODEC_MASK) ? "hda bios codec supported" : "");



		*has_pr3 = nouveau_pr3_present(pdev);

	}

}
@@ -260,6 +283,7 @@ 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;
@@ -275,14 +299,14 @@ static bool nouveau_dsm_detect(void) 
		vga_count++;



		nouveau_dsm_pci_probe(pdev, &dhandle, &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, &dhandle, &has_mux, &has_optimus,

				      &has_optimus_flags);

				      &has_optimus_flags, &has_power_resources);

	}



	/* find the optimus DSM or the old v1 DSM */
@@ -292,8 +316,11 @@ 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) {

		nouveau_dsm_priv.dhandle = dhandle;
@@ -324,7 +351,7 @@ 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)