ACPIPHP / radeon / nouveau: Remove acpi_bus_no_hotplug()

Revert parts of f244d8b6 ("ACPIPHP / radeon / nouveau: Fix VGA
switcheroo problem related to hotplug").

A previous commit 5493b31f0b55 ("PCI: Add pci_ignore_hotplug() to ignore
hotplug events for a device") added equivalent functionality implemented in
a different way for both acpiphp and pciehp.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NDave Airlie <airlied@redhat.com>
Acked-by: NRajat Jain <rajatxjain@gmail.com>

drivers/acpi/bus.c

@@ -177,16 +177,6 @@ void acpi_bus_detach_private_data(acpi_handle handle)
 }
 EXPORT_SYMBOL_GPL(acpi_bus_detach_private_data);
 
-void acpi_bus_no_hotplug(acpi_handle handle)
-{
-	struct acpi_device *adev = NULL;
-
-	acpi_bus_get_device(handle, &adev);
-	if (adev)
-		adev->flags.no_hotplug = true;
-}
-EXPORT_SYMBOL_GPL(acpi_bus_no_hotplug);
-
 static void acpi_print_osc_error(acpi_handle handle,
 	struct acpi_osc_context *context, char *error)
 {

drivers/gpu/drm/nouveau/nouveau_acpi.c

@@ -46,7 +46,6 @@ static struct nouveau_dsm_priv {
 	bool dsm_detected;
 	bool optimus_detected;
 	acpi_handle dhandle;
-	acpi_handle other_handle;
 	acpi_handle rom_handle;
 } nouveau_dsm_priv;
 
@@ -222,10 +221,9 @@ static int nouveau_dsm_pci_probe(struct pci_dev *pdev)
 	if (!dhandle)
 		return false;
 
-	if (!acpi_has_method(dhandle, "_DSM")) {
-		nouveau_dsm_priv.other_handle = dhandle;
+	if (!acpi_has_method(dhandle, "_DSM"))
 		return false;
-	}
+
 	if (acpi_check_dsm(dhandle, nouveau_dsm_muid, 0x00000102,
 			   1 << NOUVEAU_DSM_POWER))
 		retval |= NOUVEAU_DSM_HAS_MUX;
@@ -301,16 +299,6 @@ static bool nouveau_dsm_detect(void)
 		printk(KERN_INFO "VGA switcheroo: detected DSM switching method %s handle\n",
 			acpi_method_name);
 		nouveau_dsm_priv.dsm_detected = true;
-		/*
-		 * On some systems hotplug events are generated for the device
-		 * being switched off when _DSM is executed.  They cause ACPI
-		 * hotplug to trigger and attempt to remove the device from
-		 * the system, which causes it to break down.  Prevent that from
-		 * happening by setting the no_hotplug flag for the involved
-		 * ACPI device objects.
-		 */
-		acpi_bus_no_hotplug(nouveau_dsm_priv.dhandle);
-		acpi_bus_no_hotplug(nouveau_dsm_priv.other_handle);
 		ret = true;
 	}
 

drivers/gpu/drm/radeon/radeon_atpx_handler.c

@@ -33,7 +33,6 @@ static struct radeon_atpx_priv {
 	bool atpx_detected;
 	/* handle for device - and atpx */
 	acpi_handle dhandle;
-	acpi_handle other_handle;
 	struct radeon_atpx atpx;
 } radeon_atpx_priv;
 
@@ -453,10 +452,9 @@ static bool radeon_atpx_pci_probe_handle(struct pci_dev *pdev)
 		return false;
 
 	status = acpi_get_handle(dhandle, "ATPX", &atpx_handle);
-	if (ACPI_FAILURE(status)) {
-		radeon_atpx_priv.other_handle = dhandle;
+	if (ACPI_FAILURE(status))
 		return false;
-	}
+
 	radeon_atpx_priv.dhandle = dhandle;
 	radeon_atpx_priv.atpx.handle = atpx_handle;
 	return true;
@@ -540,16 +538,6 @@ static bool radeon_atpx_detect(void)
 		printk(KERN_INFO "VGA switcheroo: detected switching method %s handle\n",
 		       acpi_method_name);
 		radeon_atpx_priv.atpx_detected = true;
-		/*
-		 * On some systems hotplug events are generated for the device
-		 * being switched off when ATPX is executed.  They cause ACPI
-		 * hotplug to trigger and attempt to remove the device from
-		 * the system, which causes it to break down.  Prevent that from
-		 * happening by setting the no_hotplug flag for the involved
-		 * ACPI device objects.
-		 */
-		acpi_bus_no_hotplug(radeon_atpx_priv.dhandle);
-		acpi_bus_no_hotplug(radeon_atpx_priv.other_handle);
 		return true;
 	}
 	return false;

include/acpi/acpi_bus.h

@@ -204,10 +204,9 @@ struct acpi_device_flags {
 	u32 match_driver:1;
 	u32 initialized:1;
 	u32 visited:1;
-	u32 no_hotplug:1;
 	u32 hotplug_notify:1;
 	u32 is_dock_station:1;
-	u32 reserved:22;
+	u32 reserved:23;
 };
 
 /* File System */
@@ -412,7 +411,6 @@ void acpi_bus_private_data_handler(acpi_handle, void *);
 int acpi_bus_get_private_data(acpi_handle, void **);
 int acpi_bus_attach_private_data(acpi_handle, void *);
 void acpi_bus_detach_private_data(acpi_handle);
-void acpi_bus_no_hotplug(acpi_handle handle);
 extern int acpi_notifier_call_chain(struct acpi_device *, u32, u32);
 extern int register_acpi_notifier(struct notifier_block *);
 extern int unregister_acpi_notifier(struct notifier_block *);