drm/nouveau: make vga_switcheroo code depend on VGA_SWITCHEROO

[cascardo/linux.git] / drivers / gpu / drm / nouveau / nouveau_acpi.c

diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c
index 95c7404..d9f6120 100644 (file)
--- 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;
 
@@ -65,6 +66,7 @@ bool nouveau_is_v1_dsm(void) {
 #define NOUVEAU_DSM_HAS_MUX 0x1
 #define NOUVEAU_DSM_HAS_OPT 0x2
 
+#ifdef CONFIG_VGA_SWITCHEROO
 static const char nouveau_dsm_muid[] = {
        0xA0, 0xA0, 0x95, 0x9D, 0x60, 0x00, 0x48, 0x4D,
        0xB3, 0x4D, 0x7E, 0x5F, 0xEA, 0x12, 0x9F, 0xD4,
@@ -260,9 +262,10 @@ 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 +341,16 @@ 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;
        }
 
@@ -376,6 +389,11 @@ void nouveau_unregister_dsm_handler(void)
        if (nouveau_dsm_priv.optimus_detected || nouveau_dsm_priv.dsm_detected)
                vga_switcheroo_unregister_handler();
 }
+#else
+void nouveau_register_dsm_handler(void) {}
+void nouveau_unregister_dsm_handler(void) {}
+void nouveau_switcheroo_optimus_dsm(void) {}
+#endif
 
 /* retrieve the ROM in 4k blocks */
 static int nouveau_rom_call(acpi_handle rom_handle, uint8_t *bios,