1 files changed, 14 insertions, 2 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c
index 95c740454049..ba0183fb84f3 100644
--- a/drivers/gpu/drm/nouveau/nouveau_acpi.c
+++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c
@@ -51,6 +51,7 @@ 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;
 
@@ -260,9 +261,10 @@ static int nouveau_dsm_pci_probe(struct pci_dev *pdev)
         if (!dhandle)
                 return false;
 
-        if (!acpi_has_method(dhandle, "_DSM"))
+        if (!acpi_has_method(dhandle, "_DSM")) {
+                nouveau_dsm_priv.other_handle = dhandle;
                 return false;
-
+        }
         if (nouveau_test_dsm(dhandle, nouveau_dsm, NOUVEAU_DSM_POWER))
                 retval |= NOUVEAU_DSM_HAS_MUX;
 
@@ -338,6 +340,16 @@ 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;
         }