1 files changed, 46 insertions, 21 deletions

diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c
index c401d4936b65..5c6c708e56b8 100644
--- a/drivers/platform/x86/apple-gmux.c
+++ b/drivers/platform/x86/apple-gmux.c
@@ -57,7 +57,9 @@ struct apple_gmux_data {
 	/* switcheroo data */
 	acpi_handle dhandle;
 	int gpe;
-	enum vga_switcheroo_client_id resume_client_id;
+	enum vga_switcheroo_client_id switch_state_display;
+	enum vga_switcheroo_client_id switch_state_ddc;
+	enum vga_switcheroo_client_id switch_state_external;
 	enum vga_switcheroo_state power_state;
 	struct completion powerchange_done;
 };
@@ -368,17 +370,49 @@ static const struct backlight_ops gmux_bl_ops = {
  * for the selected GPU.
  */
 
+static void gmux_read_switch_state(struct apple_gmux_data *gmux_data)
+{
+	if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DDC) == 1)
+		gmux_data->switch_state_ddc = VGA_SWITCHEROO_IGD;
+	else
+		gmux_data->switch_state_ddc = VGA_SWITCHEROO_DIS;
+
+	if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DISPLAY) == 2)
+		gmux_data->switch_state_display = VGA_SWITCHEROO_IGD;
+	else
+		gmux_data->switch_state_display = VGA_SWITCHEROO_DIS;
+
+	if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL) == 2)
+		gmux_data->switch_state_external = VGA_SWITCHEROO_IGD;
+	else
+		gmux_data->switch_state_external = VGA_SWITCHEROO_DIS;
+}
+
+static void gmux_write_switch_state(struct apple_gmux_data *gmux_data)
+{
+	if (gmux_data->switch_state_ddc == VGA_SWITCHEROO_IGD)
+		gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 1);
+	else
+		gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 2);
+
+	if (gmux_data->switch_state_display == VGA_SWITCHEROO_IGD)
+		gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 2);
+	else
+		gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 3);
+
+	if (gmux_data->switch_state_external == VGA_SWITCHEROO_IGD)
+		gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 2);
+	else
+		gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3);
+}
+
 static int gmux_switchto(enum vga_switcheroo_client_id id)
 {
-	if (id == VGA_SWITCHEROO_IGD) {
-		gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 1);
-		gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DISPLAY, 2);
-		gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 2);
-	} else {
-		gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 2);
-		gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DISPLAY, 3);
-		gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3);
-	}
+	apple_gmux_data->switch_state_ddc = id;
+	apple_gmux_data->switch_state_display = id;
+	apple_gmux_data->switch_state_external = id;
+
+	gmux_write_switch_state(apple_gmux_data);
 
 	return 0;
 }
@@ -440,15 +474,6 @@ static int gmux_get_client_id(struct pci_dev *pdev)
 		return VGA_SWITCHEROO_DIS;
 }
 
-static enum vga_switcheroo_client_id
-gmux_active_client(struct apple_gmux_data *gmux_data)
-{
-	if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DISPLAY) == 2)
-		return VGA_SWITCHEROO_IGD;
-
-	return VGA_SWITCHEROO_DIS;
-}
-
 static const struct vga_switcheroo_handler gmux_handler = {
 	.switchto = gmux_switchto,
 	.power_state = gmux_set_power_state,
@@ -513,7 +538,6 @@ static int gmux_suspend(struct device *dev)
 	struct pnp_dev *pnp = to_pnp_dev(dev);
 	struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
 
-	gmux_data->resume_client_id = gmux_active_client(gmux_data);
 	gmux_disable_interrupts(gmux_data);
 	return 0;
 }
@@ -524,7 +548,7 @@ static int gmux_resume(struct device *dev)
 	struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
 
 	gmux_enable_interrupts(gmux_data);
-	gmux_switchto(gmux_data->resume_client_id);
+	gmux_write_switch_state(gmux_data);
 	if (gmux_data->power_state == VGA_SWITCHEROO_OFF)
 		gmux_set_discrete_state(gmux_data, gmux_data->power_state);
 	return 0;
@@ -704,6 +728,7 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
 	apple_gmux_data = gmux_data;
 	init_completion(&gmux_data->powerchange_done);
 	gmux_enable_interrupts(gmux_data);
+	gmux_read_switch_state(gmux_data);
 
 	if (vga_switcheroo_register_handler(&gmux_handler, 0)) {
 		ret = -ENODEV;