[Nouveau] [PATCH v3] drm: don't set the pci power state if the pci subsystem handles the ACPI bits

[Karol Herbst]

When looking into the runpm issues, the first workaround I came up with
was setting the PCIe link speed to whatever it was before running devinit
on the GPU.

As I was playing around with my patches today, it seems like that just
reworking the runpm bits itself fixed it on my machine as well. Hopefully
this will be enough for other laptops as well.

Anyhow, it's a nice rework and if it's not enough, we can always think
of adding the PCIe workaround later.

v2: rework detection of if Nouveau calling a DSM method or not
v3: detect old style DSM as well

Signed-off-by: Karol Herbst <kherbst at redhat.com>
Reviewed-by: Lyude Paul <lyude at redhat.com> (v2)
---
 drm/nouveau/nouveau_acpi.c |  7 ++++++-
 drm/nouveau/nouveau_acpi.h |  2 ++
 drm/nouveau/nouveau_drm.c  | 11 +++++++++--
 drm/nouveau/nouveau_drv.h  |  2 ++
 4 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/drm/nouveau/nouveau_acpi.c b/drm/nouveau/nouveau_acpi.c
index ffb195850..c483b8b21 100644
--- a/drm/nouveau/nouveau_acpi.c
+++ b/drm/nouveau/nouveau_acpi.c
@@ -358,6 +358,12 @@ void nouveau_register_dsm_handler(void)
 	vga_switcheroo_register_handler(&nouveau_dsm_handler, 0);
 }
 
+bool nouveau_runpm_calls_dsm(void)
+{
+	return (nouveau_dsm_priv.optimus_detected || nouveau_dsm_priv.dsm_detected)
+		&& !nouveau_dsm_priv.optimus_skip_dsm;
+}
+
 /* Must be called for Optimus models before the card can be turned off */
 void nouveau_switcheroo_optimus_dsm(void)
 {
@@ -371,7 +377,6 @@ void nouveau_switcheroo_optimus_dsm(void)
 
 	nouveau_optimus_dsm(nouveau_dsm_priv.dhandle, NOUVEAU_DSM_OPTIMUS_CAPS,
 		NOUVEAU_DSM_OPTIMUS_SET_POWERDOWN, &result);
-
 }
 
 void nouveau_unregister_dsm_handler(void)
diff --git a/drm/nouveau/nouveau_acpi.h b/drm/nouveau/nouveau_acpi.h
index b86294fc9..0f5d7aa03 100644
--- a/drm/nouveau/nouveau_acpi.h
+++ b/drm/nouveau/nouveau_acpi.h
@@ -13,6 +13,7 @@ void nouveau_switcheroo_optimus_dsm(void);
 int nouveau_acpi_get_bios_chunk(uint8_t *bios, int offset, int len);
 bool nouveau_acpi_rom_supported(struct device *);
 void *nouveau_acpi_edid(struct drm_device *, struct drm_connector *);
+bool nouveau_runpm_calls_dsm(void);
 #else
 static inline bool nouveau_is_optimus(void) { return false; };
 static inline bool nouveau_is_v1_dsm(void) { return false; };
@@ -22,6 +23,7 @@ static inline void nouveau_switcheroo_optimus_dsm(void) {}
 static inline bool nouveau_acpi_rom_supported(struct device *dev) { return false; }
 static inline int nouveau_acpi_get_bios_chunk(uint8_t *bios, int offset, int len) { return -EINVAL; }
 static inline void *nouveau_acpi_edid(struct drm_device *dev, struct drm_connector *connector) { return NULL; }
+static inline bool nouveau_runpm_calls_dsm(void) { return false; }
 #endif
 
 #endif
diff --git a/drm/nouveau/nouveau_drm.c b/drm/nouveau/nouveau_drm.c
index f74557af9..537af50e8 100644
--- a/drm/nouveau/nouveau_drm.c
+++ b/drm/nouveau/nouveau_drm.c
@@ -557,6 +557,7 @@ nouveau_drm_device_init(struct drm_device *dev)
 	nouveau_fbcon_init(dev);
 	nouveau_led_init(dev);
 
+	drm->runpm_dsm = nouveau_runpm_calls_dsm();
 	if (nouveau_pmops_runtime()) {
 		pm_runtime_use_autosuspend(dev->dev);
 		pm_runtime_set_autosuspend_delay(dev->dev, 5000);
@@ -910,6 +911,7 @@ nouveau_pmops_runtime_suspend(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct drm_device *drm_dev = pci_get_drvdata(pdev);
+	struct nouveau_drm *drm = nouveau_drm(drm_dev);
 	int ret;
 
 	if (!nouveau_pmops_runtime()) {
@@ -917,12 +919,15 @@ nouveau_pmops_runtime_suspend(struct device *dev)
 		return -EBUSY;
 	}
 
+	drm_dev->switch_power_state = DRM_SWITCH_POWER_CHANGING;
 	nouveau_switcheroo_optimus_dsm();
 	ret = nouveau_do_suspend(drm_dev, true);
 	pci_save_state(pdev);
 	pci_disable_device(pdev);
 	pci_ignore_hotplug(pdev);
-	pci_set_power_state(pdev, PCI_D3cold);
+	if (drm->runpm_dsm)
+		pci_set_power_state(pdev, PCI_D3cold);
+
 	drm_dev->switch_power_state = DRM_SWITCH_POWER_DYNAMIC_OFF;
 	return ret;
 }
@@ -941,7 +946,9 @@ nouveau_pmops_runtime_resume(struct device *dev)
 		return -EBUSY;
 	}
 
-	pci_set_power_state(pdev, PCI_D0);
+	drm_dev->switch_power_state = DRM_SWITCH_POWER_CHANGING;
+	if (drm->runpm_dsm)
+		pci_set_power_state(pdev, PCI_D0);
 	pci_restore_state(pdev);
 	ret = pci_enable_device(pdev);
 	if (ret)
diff --git a/drm/nouveau/nouveau_drv.h b/drm/nouveau/nouveau_drv.h
index e6665354e..1e4376128 100644
--- a/drm/nouveau/nouveau_drv.h
+++ b/drm/nouveau/nouveau_drv.h
@@ -216,6 +216,8 @@ struct nouveau_drm {
 	struct nouveau_svm *svm;
 
 	struct nouveau_dmem *dmem;
+
+	bool runpm_dsm;
 };
 
 static inline struct nouveau_drm *
-- 
2.21.0