These changes are the raw update to linux-4.4.6-rt14. Kernel sources

are taken from kernel.org, and rt patch from the rt wiki download page.

During the rebasing, the following patch collided:

Force tick interrupt and get rid of softirq magic(I70131fb85).

Collisions have been removed because its logic was found on the
source already.

Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>

2 files changed, 462 insertions, 153 deletions

diff --git a/kernel/drivers/gpu/vga/vga_switcheroo.c b/kernel/drivers/gpu/vga/vga_switcheroo.c
index 37ac7b5db..41edd5a3f 100644
--- a/kernel/drivers/gpu/vga/vga_switcheroo.c
+++ b/kernel/drivers/gpu/vga/vga_switcheroo.c
@@ -1,51 +1,135 @@
 /*
+ * vga_switcheroo.c - Support for laptop with dual GPU using one set of outputs
+ *
  * Copyright (c) 2010 Red Hat Inc.
  * Author : Dave Airlie <airlied@redhat.com>
  *
+ * Copyright (c) 2015 Lukas Wunner <lukas@wunner.de>
  *
- * Licensed under GPLv2
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS
+ * IN THE SOFTWARE.
  *
- * vga_switcheroo.c - Support for laptop with dual GPU using one set of outputs
-
- Switcher interface - methods require for ATPX and DCM
- - switchto - this throws the output MUX switch
- - discrete_set_power - sets the power state for the discrete card
-
- GPU driver interface
- - set_gpu_state - this should do the equiv of s/r for the card
-		  - this should *not* set the discrete power state
- - switch_check  - check if the device is in a position to switch now
  */
 
-#include <linux/module.h>
-#include <linux/seq_file.h>
-#include <linux/uaccess.h>
-#include <linux/fs.h>
+#define pr_fmt(fmt) "vga_switcheroo: " fmt
+
+#include <linux/console.h>
 #include <linux/debugfs.h>
 #include <linux/fb.h>
-
+#include <linux/fs.h>
+#include <linux/module.h>
 #include <linux/pci.h>
-#include <linux/console.h>
-#include <linux/vga_switcheroo.h>
 #include <linux/pm_runtime.h>
-
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
 #include <linux/vgaarb.h>
+#include <linux/vga_switcheroo.h>
+
+/**
+ * DOC: Overview
+ *
+ * vga_switcheroo is the Linux subsystem for laptop hybrid graphics.
+ * These come in two flavors:
+ *
+ * * muxed: Dual GPUs with a multiplexer chip to switch outputs between GPUs.
+ * * muxless: Dual GPUs but only one of them is connected to outputs.
+ * 	The other one is merely used to offload rendering, its results
+ * 	are copied over PCIe into the framebuffer. On Linux this is
+ * 	supported with DRI PRIME.
+ *
+ * Hybrid graphics started to appear in the late Naughties and were initially
+ * all muxed. Newer laptops moved to a muxless architecture for cost reasons.
+ * A notable exception is the MacBook Pro which continues to use a mux.
+ * Muxes come with varying capabilities: Some switch only the panel, others
+ * can also switch external displays. Some switch all display pins at once
+ * while others can switch just the DDC lines. (To allow EDID probing
+ * for the inactive GPU.) Also, muxes are often used to cut power to the
+ * discrete GPU while it is not used.
+ *
+ * DRM drivers register GPUs with vga_switcheroo, these are heretoforth called
+ * clients. The mux is called the handler. Muxless machines also register a
+ * handler to control the power state of the discrete GPU, its ->switchto
+ * callback is a no-op for obvious reasons. The discrete GPU is often equipped
+ * with an HDA controller for the HDMI/DP audio signal, this will also
+ * register as a client so that vga_switcheroo can take care of the correct
+ * suspend/resume order when changing the discrete GPU's power state. In total
+ * there can thus be up to three clients: Two vga clients (GPUs) and one audio
+ * client (on the discrete GPU). The code is mostly prepared to support
+ * machines with more than two GPUs should they become available.
+ * The GPU to which the outputs are currently switched is called the
+ * active client in vga_switcheroo parlance. The GPU not in use is the
+ * inactive client.
+ */
 
+/**
+ * struct vga_switcheroo_client - registered client
+ * @pdev: client pci device
+ * @fb_info: framebuffer to which console is remapped on switching
+ * @pwr_state: current power state
+ * @ops: client callbacks
+ * @id: client identifier. Determining the id requires the handler,
+ * 	so gpus are initially assigned VGA_SWITCHEROO_UNKNOWN_ID
+ * 	and later given their true id in vga_switcheroo_enable()
+ * @active: whether the outputs are currently switched to this client
+ * @driver_power_control: whether power state is controlled by the driver's
+ * 	runtime pm. If true, writing ON and OFF to the vga_switcheroo debugfs
+ * 	interface is a no-op so as not to interfere with runtime pm
+ * @list: client list
+ *
+ * Registered client. A client can be either a GPU or an audio device on a GPU.
+ * For audio clients, the @fb_info, @active and @driver_power_control members
+ * are bogus.
+ */
 struct vga_switcheroo_client {
 	struct pci_dev *pdev;
 	struct fb_info *fb_info;
-	int pwr_state;
+	enum vga_switcheroo_state pwr_state;
 	const struct vga_switcheroo_client_ops *ops;
-	int id;
+	enum vga_switcheroo_client_id id;
 	bool active;
 	bool driver_power_control;
 	struct list_head list;
 };
 
+/*
+ * protects access to struct vgasr_priv
+ */
 static DEFINE_MUTEX(vgasr_mutex);
 
+/**
+ * struct vgasr_priv - vga_switcheroo private data
+ * @active: whether vga_switcheroo is enabled.
+ * 	Prerequisite is the registration of two GPUs and a handler
+ * @delayed_switch_active: whether a delayed switch is pending
+ * @delayed_client_id: client to which a delayed switch is pending
+ * @debugfs_root: directory for vga_switcheroo debugfs interface
+ * @switch_file: file for vga_switcheroo debugfs interface
+ * @registered_clients: number of registered GPUs
+ * 	(counting only vga clients, not audio clients)
+ * @clients: list of registered clients
+ * @handler: registered handler
+ *
+ * vga_switcheroo private data. Currently only one vga_switcheroo instance
+ * per system is supported.
+ */
 struct vgasr_priv {
-
 	bool active;
 	bool delayed_switch_active;
 	enum vga_switcheroo_client_id delayed_client_id;
@@ -56,12 +140,13 @@ struct vgasr_priv {
 	int registered_clients;
 	struct list_head clients;
 
-	struct vga_switcheroo_handler *handler;
+	const struct vga_switcheroo_handler *handler;
 };
 
 #define ID_BIT_AUDIO		0x100
 #define client_is_audio(c)	((c)->id & ID_BIT_AUDIO)
-#define client_is_vga(c)	((c)->id == -1 || !client_is_audio(c))
+#define client_is_vga(c)	((c)->id == VGA_SWITCHEROO_UNKNOWN_ID || \
+				 !client_is_audio(c))
 #define client_id(c)		((c)->id & ~ID_BIT_AUDIO)
 
 static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv);
@@ -89,7 +174,7 @@ static void vga_switcheroo_enable(void)
 		vgasr_priv.handler->init();
 
 	list_for_each_entry(client, &vgasr_priv.clients, list) {
-		if (client->id != -1)
+		if (client->id != VGA_SWITCHEROO_UNKNOWN_ID)
 			continue;
 		ret = vgasr_priv.handler->get_client_id(client->pdev);
 		if (ret < 0)
@@ -101,7 +186,16 @@ static void vga_switcheroo_enable(void)
 	vgasr_priv.active = true;
 }
 
-int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler)
+/**
+ * vga_switcheroo_register_handler() - register handler
+ * @handler: handler callbacks
+ *
+ * Register handler. Enable vga_switcheroo if two vga clients have already
+ * registered.
+ *
+ * Return: 0 on success, -EINVAL if a handler was already registered.
+ */
+int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler)
 {
 	mutex_lock(&vgasr_mutex);
 	if (vgasr_priv.handler) {
@@ -111,7 +205,7 @@ int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler)
 
 	vgasr_priv.handler = handler;
 	if (vga_switcheroo_ready()) {
-		printk(KERN_INFO "vga_switcheroo: enabled\n");
+		pr_info("enabled\n");
 		vga_switcheroo_enable();
 	}
 	mutex_unlock(&vgasr_mutex);
@@ -119,12 +213,17 @@ int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler)
 }
 EXPORT_SYMBOL(vga_switcheroo_register_handler);
 
+/**
+ * vga_switcheroo_unregister_handler() - unregister handler
+ *
+ * Unregister handler. Disable vga_switcheroo.
+ */
 void vga_switcheroo_unregister_handler(void)
 {
 	mutex_lock(&vgasr_mutex);
 	vgasr_priv.handler = NULL;
 	if (vgasr_priv.active) {
-		pr_info("vga_switcheroo: disabled\n");
+		pr_info("disabled\n");
 		vga_switcheroo_debugfs_fini(&vgasr_priv);
 		vgasr_priv.active = false;
 	}
@@ -134,7 +233,8 @@ EXPORT_SYMBOL(vga_switcheroo_unregister_handler);
 
 static int register_client(struct pci_dev *pdev,
 			   const struct vga_switcheroo_client_ops *ops,
-			   int id, bool active, bool driver_power_control)
+			   enum vga_switcheroo_client_id id, bool active,
+			   bool driver_power_control)
 {
 	struct vga_switcheroo_client *client;
 
@@ -155,27 +255,52 @@ static int register_client(struct pci_dev *pdev,
 		vgasr_priv.registered_clients++;
 
 	if (vga_switcheroo_ready()) {
-		printk(KERN_INFO "vga_switcheroo: enabled\n");
+		pr_info("enabled\n");
 		vga_switcheroo_enable();
 	}
 	mutex_unlock(&vgasr_mutex);
 	return 0;
 }
 
+/**
+ * vga_switcheroo_register_client - register vga client
+ * @pdev: client pci device
+ * @ops: client callbacks
+ * @driver_power_control: whether power state is controlled by the driver's
+ * 	runtime pm
+ *
+ * Register vga client (GPU). Enable vga_switcheroo if another GPU and a
+ * handler have already registered. The power state of the client is assumed
+ * to be ON.
+ *
+ * Return: 0 on success, -ENOMEM on memory allocation error.
+ */
 int vga_switcheroo_register_client(struct pci_dev *pdev,
 				   const struct vga_switcheroo_client_ops *ops,
 				   bool driver_power_control)
 {
-	return register_client(pdev, ops, -1,
-			       pdev == vga_default_device(), driver_power_control);
+	return register_client(pdev, ops, VGA_SWITCHEROO_UNKNOWN_ID,
+			       pdev == vga_default_device(),
+			       driver_power_control);
 }
 EXPORT_SYMBOL(vga_switcheroo_register_client);
 
+/**
+ * vga_switcheroo_register_audio_client - register audio client
+ * @pdev: client pci device
+ * @ops: client callbacks
+ * @id: client identifier
+ *
+ * Register audio client (audio device on a GPU). The power state of the
+ * client is assumed to be ON.
+ *
+ * Return: 0 on success, -ENOMEM on memory allocation error.
+ */
 int vga_switcheroo_register_audio_client(struct pci_dev *pdev,
 					 const struct vga_switcheroo_client_ops *ops,
-					 int id, bool active)
+					 enum vga_switcheroo_client_id id)
 {
-	return register_client(pdev, ops, id | ID_BIT_AUDIO, active, false);
+	return register_client(pdev, ops, id | ID_BIT_AUDIO, false, false);
 }
 EXPORT_SYMBOL(vga_switcheroo_register_audio_client);
 
@@ -183,6 +308,7 @@ static struct vga_switcheroo_client *
 find_client_from_pci(struct list_head *head, struct pci_dev *pdev)
 {
 	struct vga_switcheroo_client *client;
+
 	list_for_each_entry(client, head, list)
 		if (client->pdev == pdev)
 			return client;
@@ -190,9 +316,11 @@ find_client_from_pci(struct list_head *head, struct pci_dev *pdev)
 }
 
 static struct vga_switcheroo_client *
-find_client_from_id(struct list_head *head, int client_id)
+find_client_from_id(struct list_head *head,
+		    enum vga_switcheroo_client_id client_id)
 {
 	struct vga_switcheroo_client *client;
+
 	list_for_each_entry(client, head, list)
 		if (client->id == client_id)
 			return client;
@@ -203,25 +331,44 @@ static struct vga_switcheroo_client *
 find_active_client(struct list_head *head)
 {
 	struct vga_switcheroo_client *client;
+
 	list_for_each_entry(client, head, list)
-		if (client->active && client_is_vga(client))
+		if (client->active)
 			return client;
 	return NULL;
 }
 
-int vga_switcheroo_get_client_state(struct pci_dev *pdev)
+/**
+ * vga_switcheroo_get_client_state() - obtain power state of a given client
+ * @pdev: client pci device
+ *
+ * Obtain power state of a given client as seen from vga_switcheroo.
+ * The function is only called from hda_intel.c.
+ *
+ * Return: Power state.
+ */
+enum vga_switcheroo_state vga_switcheroo_get_client_state(struct pci_dev *pdev)
 {
 	struct vga_switcheroo_client *client;
+	enum vga_switcheroo_state ret;
 
+	mutex_lock(&vgasr_mutex);
 	client = find_client_from_pci(&vgasr_priv.clients, pdev);
 	if (!client)
-		return VGA_SWITCHEROO_NOT_FOUND;
-	if (!vgasr_priv.active)
-		return VGA_SWITCHEROO_INIT;
-	return client->pwr_state;
+		ret = VGA_SWITCHEROO_NOT_FOUND;
+	else
+		ret = client->pwr_state;
+	mutex_unlock(&vgasr_mutex);
+	return ret;
 }
 EXPORT_SYMBOL(vga_switcheroo_get_client_state);
 
+/**
+ * vga_switcheroo_unregister_client() - unregister client
+ * @pdev: client pci device
+ *
+ * Unregister client. Disable vga_switcheroo if this is a vga client (GPU).
+ */
 void vga_switcheroo_unregister_client(struct pci_dev *pdev)
 {
 	struct vga_switcheroo_client *client;
@@ -235,7 +382,7 @@ void vga_switcheroo_unregister_client(struct pci_dev *pdev)
 		kfree(client);
 	}
 	if (vgasr_priv.active && vgasr_priv.registered_clients < 2) {
-		printk(KERN_INFO "vga_switcheroo: disabled\n");
+		pr_info("disabled\n");
 		vga_switcheroo_debugfs_fini(&vgasr_priv);
 		vgasr_priv.active = false;
 	}
@@ -243,6 +390,14 @@ void vga_switcheroo_unregister_client(struct pci_dev *pdev)
 }
 EXPORT_SYMBOL(vga_switcheroo_unregister_client);
 
+/**
+ * vga_switcheroo_client_fb_set() - set framebuffer of a given client
+ * @pdev: client pci device
+ * @info: framebuffer
+ *
+ * Set framebuffer of a given client. The console will be remapped to this
+ * on switching.
+ */
 void vga_switcheroo_client_fb_set(struct pci_dev *pdev,
 				 struct fb_info *info)
 {
@@ -256,14 +411,52 @@ void vga_switcheroo_client_fb_set(struct pci_dev *pdev,
 }
 EXPORT_SYMBOL(vga_switcheroo_client_fb_set);
 
+/**
+ * DOC: Manual switching and manual power control
+ *
+ * In this mode of use, the file /sys/kernel/debug/vgaswitcheroo/switch
+ * can be read to retrieve the current vga_switcheroo state and commands
+ * can be written to it to change the state. The file appears as soon as
+ * two GPU drivers and one handler have registered with vga_switcheroo.
+ * The following commands are understood:
+ *
+ * * OFF: Power off the device not in use.
+ * * ON: Power on the device not in use.
+ * * IGD: Switch to the integrated graphics device.
+ * 	Power on the integrated GPU if necessary, power off the discrete GPU.
+ * 	Prerequisite is that no user space processes (e.g. Xorg, alsactl)
+ * 	have opened device files of the GPUs or the audio client. If the
+ * 	switch fails, the user may invoke lsof(8) or fuser(1) on /dev/dri/
+ * 	and /dev/snd/controlC1 to identify processes blocking the switch.
+ * * DIS: Switch to the discrete graphics device.
+ * * DIGD: Delayed switch to the integrated graphics device.
+ * 	This will perform the switch once the last user space process has
+ * 	closed the device files of the GPUs and the audio client.
+ * * DDIS: Delayed switch to the discrete graphics device.
+ * * MIGD: Mux-only switch to the integrated graphics device.
+ * 	Does not remap console or change the power state of either gpu.
+ * 	If the integrated GPU is currently off, the screen will turn black.
+ * 	If it is on, the screen will show whatever happens to be in VRAM.
+ * 	Either way, the user has to blindly enter the command to switch back.
+ * * MDIS: Mux-only switch to the discrete graphics device.
+ *
+ * For GPUs whose power state is controlled by the driver's runtime pm,
+ * the ON and OFF commands are a no-op (see next section).
+ *
+ * For muxless machines, the IGD/DIS, DIGD/DDIS and MIGD/MDIS commands
+ * should not be used.
+ */
+
 static int vga_switcheroo_show(struct seq_file *m, void *v)
 {
 	struct vga_switcheroo_client *client;
 	int i = 0;
+
 	mutex_lock(&vgasr_mutex);
 	list_for_each_entry(client, &vgasr_priv.clients, list) {
 		seq_printf(m, "%d:%s%s:%c:%s%s:%s\n", i,
-			   client_id(client) == VGA_SWITCHEROO_DIS ? "DIS" : "IGD",
+			   client_id(client) == VGA_SWITCHEROO_DIS ? "DIS" :
+								     "IGD",
 			   client_is_vga(client) ? "" : "-Audio",
 			   client->active ? '+' : ' ',
 			   client->driver_power_control ? "Dyn" : "",
@@ -304,7 +497,8 @@ static int vga_switchoff(struct vga_switcheroo_client *client)
 	return 0;
 }
 
-static void set_audio_state(int id, int state)
+static void set_audio_state(enum vga_switcheroo_client_id id,
+			    enum vga_switcheroo_state state)
 {
 	struct vga_switcheroo_client *client;
 
@@ -347,6 +541,7 @@ static int vga_switchto_stage2(struct vga_switcheroo_client *new_client)
 
 	if (new_client->fb_info) {
 		struct fb_event event;
+
 		console_lock();
 		event.info = new_client->fb_info;
 		fb_notifier_call_chain(FB_EVENT_REMAP_ALL_CONSOLE, &event);
@@ -375,7 +570,7 @@ static bool check_can_switch(void)
 
 	list_for_each_entry(client, &vgasr_priv.clients, list) {
 		if (!client->ops->can_switch(client->pdev)) {
-			printk(KERN_ERR "vga_switcheroo: client %x refused switch\n", client->id);
+			pr_err("client %x refused switch\n", client->id);
 			return false;
 		}
 	}
@@ -390,7 +585,7 @@ vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf,
 	int ret;
 	bool delay = false, can_switch;
 	bool just_mux = false;
-	int client_id = -1;
+	enum vga_switcheroo_client_id client_id = VGA_SWITCHEROO_UNKNOWN_ID;
 	struct vga_switcheroo_client *client = NULL;
 
 	if (cnt > 63)
@@ -459,7 +654,7 @@ vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf,
 		client_id = VGA_SWITCHEROO_DIS;
 	}
 
-	if (client_id == -1)
+	if (client_id == VGA_SWITCHEROO_UNKNOWN_ID)
 		goto out;
 	client = find_client_from_id(&vgasr_priv.clients, client_id);
 	if (!client)
@@ -484,20 +679,20 @@ vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf,
 	if (can_switch) {
 		ret = vga_switchto_stage1(client);
 		if (ret)
-			printk(KERN_ERR "vga_switcheroo: switching failed stage 1 %d\n", ret);
+			pr_err("switching failed stage 1 %d\n", ret);
 
 		ret = vga_switchto_stage2(client);
 		if (ret)
-			printk(KERN_ERR "vga_switcheroo: switching failed stage 2 %d\n", ret);
+			pr_err("switching failed stage 2 %d\n", ret);
 
 	} else {
-		printk(KERN_INFO "vga_switcheroo: setting delayed switch to client %d\n", client->id);
+		pr_info("setting delayed switch to client %d\n", client->id);
 		vgasr_priv.delayed_switch_active = true;
 		vgasr_priv.delayed_client_id = client_id;
 
 		ret = vga_switchto_stage1(client);
 		if (ret)
-			printk(KERN_ERR "vga_switcheroo: delayed switching stage 1 failed %d\n", ret);
+			pr_err("delayed switching stage 1 failed %d\n", ret);
 	}
 
 out:
@@ -516,32 +711,32 @@ static const struct file_operations vga_switcheroo_debugfs_fops = {
 
 static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv)
 {
-	if (priv->switch_file) {
-		debugfs_remove(priv->switch_file);
-		priv->switch_file = NULL;
-	}
-	if (priv->debugfs_root) {
-		debugfs_remove(priv->debugfs_root);
-		priv->debugfs_root = NULL;
-	}
+	debugfs_remove(priv->switch_file);
+	priv->switch_file = NULL;
+
+	debugfs_remove(priv->debugfs_root);
+	priv->debugfs_root = NULL;
 }
 
 static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv)
 {
+	static const char mp[] = "/sys/kernel/debug";
+
 	/* already initialised */
 	if (priv->debugfs_root)
 		return 0;
 	priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL);
 
 	if (!priv->debugfs_root) {
-		printk(KERN_ERR "vga_switcheroo: Cannot create /sys/kernel/debug/vgaswitcheroo\n");
+		pr_err("Cannot create %s/vgaswitcheroo\n", mp);
 		goto fail;
 	}
 
 	priv->switch_file = debugfs_create_file("switch", 0644,
-						priv->debugfs_root, NULL, &vga_switcheroo_debugfs_fops);
+						priv->debugfs_root, NULL,
+						&vga_switcheroo_debugfs_fops);
 	if (!priv->switch_file) {
-		printk(KERN_ERR "vga_switcheroo: cannot create /sys/kernel/debug/vgaswitcheroo/switch\n");
+		pr_err("cannot create %s/vgaswitcheroo/switch\n", mp);
 		goto fail;
 	}
 	return 0;
@@ -550,6 +745,16 @@ fail:
 	return -1;
 }
 
+/**
+ * vga_switcheroo_process_delayed_switch() - helper for delayed switching
+ *
+ * Process a delayed switch if one is pending. DRM drivers should call this
+ * from their ->lastclose callback.
+ *
+ * Return: 0 on success. -EINVAL if no delayed switch is pending, if the client
+ * has unregistered in the meantime or if there are other clients blocking the
+ * switch. If the actual switch fails, an error is reported and 0 is returned.
+ */
 int vga_switcheroo_process_delayed_switch(void)
 {
 	struct vga_switcheroo_client *client;
@@ -560,7 +765,8 @@ int vga_switcheroo_process_delayed_switch(void)
 	if (!vgasr_priv.delayed_switch_active)
 		goto err;
 
-	printk(KERN_INFO "vga_switcheroo: processing delayed switch to %d\n", vgasr_priv.delayed_client_id);
+	pr_info("processing delayed switch to %d\n",
+		vgasr_priv.delayed_client_id);
 
 	client = find_client_from_id(&vgasr_priv.clients,
 				     vgasr_priv.delayed_client_id);
@@ -569,7 +775,7 @@ int vga_switcheroo_process_delayed_switch(void)
 
 	ret = vga_switchto_stage2(client);
 	if (ret)
-		printk(KERN_ERR "vga_switcheroo: delayed switching failed stage 2 %d\n", ret);
+		pr_err("delayed switching failed stage 2 %d\n", ret);
 
 	vgasr_priv.delayed_switch_active = false;
 	err = 0;
@@ -579,7 +785,41 @@ err:
 }
 EXPORT_SYMBOL(vga_switcheroo_process_delayed_switch);
 
-static void vga_switcheroo_power_switch(struct pci_dev *pdev, enum vga_switcheroo_state state)
+/**
+ * DOC: Driver power control
+ *
+ * In this mode of use, the discrete GPU automatically powers up and down at
+ * the discretion of the driver's runtime pm. On muxed machines, the user may
+ * still influence the muxer state by way of the debugfs interface, however
+ * the ON and OFF commands become a no-op for the discrete GPU.
+ *
+ * This mode is the default on Nvidia HybridPower/Optimus and ATI PowerXpress.
+ * Specifying nouveau.runpm=0, radeon.runpm=0 or amdgpu.runpm=0 on the kernel
+ * command line disables it.
+ *
+ * When the driver decides to power up or down, it notifies vga_switcheroo
+ * thereof so that it can (a) power the audio device on the GPU up or down,
+ * and (b) update its internal power state representation for the device.
+ * This is achieved by vga_switcheroo_set_dynamic_switch().
+ *
+ * After the GPU has been suspended, the handler needs to be called to cut
+ * power to the GPU. Likewise it needs to reinstate power before the GPU
+ * can resume. This is achieved by vga_switcheroo_init_domain_pm_ops(),
+ * which augments the GPU's suspend/resume functions by the requisite
+ * calls to the handler.
+ *
+ * When the audio device resumes, the GPU needs to be woken. This is achieved
+ * by vga_switcheroo_init_domain_pm_optimus_hdmi_audio(), which augments the
+ * audio device's resume function.
+ *
+ * On muxed machines, if the mux is initially switched to the discrete GPU,
+ * the user ends up with a black screen when the GPU powers down after boot.
+ * As a workaround, the mux is forced to the integrated GPU on runtime suspend,
+ * cf. https://bugs.freedesktop.org/show_bug.cgi?id=75917
+ */
+
+static void vga_switcheroo_power_switch(struct pci_dev *pdev,
+					enum vga_switcheroo_state state)
 {
 	struct vga_switcheroo_client *client;
 
@@ -596,21 +836,32 @@ static void vga_switcheroo_power_switch(struct pci_dev *pdev, enum vga_switchero
 	vgasr_priv.handler->power_state(client->id, state);
 }
 
-/* force a PCI device to a certain state - mainly to turn off audio clients */
-
-void vga_switcheroo_set_dynamic_switch(struct pci_dev *pdev, enum vga_switcheroo_state dynamic)
+/**
+ * vga_switcheroo_set_dynamic_switch() - helper for driver power control
+ * @pdev: client pci device
+ * @dynamic: new power state
+ *
+ * Helper for GPUs whose power state is controlled by the driver's runtime pm.
+ * When the driver decides to power up or down, it notifies vga_switcheroo
+ * thereof using this helper so that it can (a) power the audio device on
+ * the GPU up or down, and (b) update its internal power state representation
+ * for the device.
+ */
+void vga_switcheroo_set_dynamic_switch(struct pci_dev *pdev,
+				       enum vga_switcheroo_state dynamic)
 {
 	struct vga_switcheroo_client *client;
 
+	mutex_lock(&vgasr_mutex);
 	client = find_client_from_pci(&vgasr_priv.clients, pdev);
-	if (!client)
-		return;
-
-	if (!client->driver_power_control)
+	if (!client || !client->driver_power_control) {
+		mutex_unlock(&vgasr_mutex);
 		return;
+	}
 
 	client->pwr_state = dynamic;
 	set_audio_state(client->id, dynamic);
+	mutex_unlock(&vgasr_mutex);
 }
 EXPORT_SYMBOL(vga_switcheroo_set_dynamic_switch);
 
@@ -623,9 +874,11 @@ static int vga_switcheroo_runtime_suspend(struct device *dev)
 	ret = dev->bus->pm->runtime_suspend(dev);
 	if (ret)
 		return ret;
+	mutex_lock(&vgasr_mutex);
 	if (vgasr_priv.handler->switchto)
 		vgasr_priv.handler->switchto(VGA_SWITCHEROO_IGD);
 	vga_switcheroo_power_switch(pdev, VGA_SWITCHEROO_OFF);
+	mutex_unlock(&vgasr_mutex);
 	return 0;
 }
 
@@ -634,7 +887,9 @@ static int vga_switcheroo_runtime_resume(struct device *dev)
 	struct pci_dev *pdev = to_pci_dev(dev);
 	int ret;
 
+	mutex_lock(&vgasr_mutex);
 	vga_switcheroo_power_switch(pdev, VGA_SWITCHEROO_ON);
+	mutex_unlock(&vgasr_mutex);
 	ret = dev->bus->pm->runtime_resume(dev);
 	if (ret)
 		return ret;
@@ -642,9 +897,20 @@ static int vga_switcheroo_runtime_resume(struct device *dev)
 	return 0;
 }
 
-/* this version is for the case where the power switch is separate
-   to the device being powered down. */
-int vga_switcheroo_init_domain_pm_ops(struct device *dev, struct dev_pm_domain *domain)
+/**
+ * vga_switcheroo_init_domain_pm_ops() - helper for driver power control
+ * @dev: vga client device
+ * @domain: power domain
+ *
+ * Helper for GPUs whose power state is controlled by the driver's runtime pm.
+ * After the GPU has been suspended, the handler needs to be called to cut
+ * power to the GPU. Likewise it needs to reinstate power before the GPU
+ * can resume. To this end, this helper augments the suspend/resume functions
+ * by the requisite calls to the handler. It needs only be called on platforms
+ * where the power switch is separate to the device being powered down.
+ */
+int vga_switcheroo_init_domain_pm_ops(struct device *dev,
+				      struct dev_pm_domain *domain)
 {
 	/* copy over all the bus versions */
 	if (dev->bus && dev->bus->pm) {
@@ -669,38 +935,59 @@ EXPORT_SYMBOL(vga_switcheroo_fini_domain_pm_ops);
 static int vga_switcheroo_runtime_resume_hdmi_audio(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
+	struct vga_switcheroo_client *client;
+	struct device *video_dev = NULL;
 	int ret;
-	struct vga_switcheroo_client *client, *found = NULL;
 
 	/* we need to check if we have to switch back on the video
 	   device so the audio device can come back */
+	mutex_lock(&vgasr_mutex);
 	list_for_each_entry(client, &vgasr_priv.clients, list) {
-		if (PCI_SLOT(client->pdev->devfn) == PCI_SLOT(pdev->devfn) && client_is_vga(client)) {
-			found = client;
-			ret = pm_runtime_get_sync(&client->pdev->dev);
-			if (ret) {
-				if (ret != 1)
-					return ret;
-			}
+		if (PCI_SLOT(client->pdev->devfn) == PCI_SLOT(pdev->devfn) &&
+		    client_is_vga(client)) {
+			video_dev = &client->pdev->dev;
 			break;
 		}
 	}
+	mutex_unlock(&vgasr_mutex);
+
+	if (video_dev) {
+		ret = pm_runtime_get_sync(video_dev);
+		if (ret && ret != 1)
+			return ret;
+	}
 	ret = dev->bus->pm->runtime_resume(dev);
 
 	/* put the reference for the gpu */
-	if (found) {
-		pm_runtime_mark_last_busy(&found->pdev->dev);
-		pm_runtime_put_autosuspend(&found->pdev->dev);
+	if (video_dev) {
+		pm_runtime_mark_last_busy(video_dev);
+		pm_runtime_put_autosuspend(video_dev);
 	}
 	return ret;
 }
 
-int vga_switcheroo_init_domain_pm_optimus_hdmi_audio(struct device *dev, struct dev_pm_domain *domain)
+/**
+ * vga_switcheroo_init_domain_pm_optimus_hdmi_audio() - helper for driver
+ * 	power control
+ * @dev: audio client device
+ * @domain: power domain
+ *
+ * Helper for GPUs whose power state is controlled by the driver's runtime pm.
+ * When the audio device resumes, the GPU needs to be woken. This helper
+ * augments the audio device's resume function to do that.
+ *
+ * Return: 0 on success, -EINVAL if no power management operations are
+ * defined for this device.
+ */
+int
+vga_switcheroo_init_domain_pm_optimus_hdmi_audio(struct device *dev,
+						 struct dev_pm_domain *domain)
 {
 	/* copy over all the bus versions */
 	if (dev->bus && dev->bus->pm) {
 		domain->ops = *dev->bus->pm;
-		domain->ops.runtime_resume = vga_switcheroo_runtime_resume_hdmi_audio;
+		domain->ops.runtime_resume =
+			vga_switcheroo_runtime_resume_hdmi_audio;
 
 		dev->pm_domain = domain;
 		return 0;
diff --git a/kernel/drivers/gpu/vga/vgaarb.c b/kernel/drivers/gpu/vga/vgaarb.c
index 7bcbf8636..9abcaa53b 100644
--- a/kernel/drivers/gpu/vga/vgaarb.c
+++ b/kernel/drivers/gpu/vga/vgaarb.c
@@ -29,6 +29,8 @@
  *
  */
 
+#define pr_fmt(fmt) "vgaarb: " fmt
+
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/pci.h>
@@ -134,7 +136,6 @@ struct pci_dev *vga_default_device(void)
 {
 	return vga_default;
 }
-
 EXPORT_SYMBOL_GPL(vga_default_device);
 
 void vga_set_default_device(struct pci_dev *pdev)
@@ -298,9 +299,9 @@ enable_them:
 
 	pci_set_vga_state(vgadev->pdev, true, pci_bits, flags);
 
-	if (!vgadev->bridge_has_one_vga) {
+	if (!vgadev->bridge_has_one_vga)
 		vga_irq_set_state(vgadev, true);
-	}
+
 	vgadev->owns |= wants;
 lock_them:
 	vgadev->locks |= (rsrc & VGA_RSRC_LEGACY_MASK);
@@ -394,8 +395,10 @@ int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible)
 		set_current_state(interruptible ?
 				  TASK_INTERRUPTIBLE :
 				  TASK_UNINTERRUPTIBLE);
-		if (signal_pending(current)) {
-			rc = -EINTR;
+		if (interruptible && signal_pending(current)) {
+			__set_current_state(TASK_RUNNING);
+			remove_wait_queue(&vga_wait_queue, &wait);
+			rc = -ERESTARTSYS;
 			break;
 		}
 		schedule();
@@ -452,15 +455,15 @@ bail:
 }
 EXPORT_SYMBOL(vga_put);
 
-/* Rules for using a bridge to control a VGA descendant decoding:
-   if a bridge has only one VGA descendant then it can be used
-   to control the VGA routing for that device.
-   It should always use the bridge closest to the device to control it.
-   If a bridge has a direct VGA descendant, but also have a sub-bridge
-   VGA descendant then we cannot use that bridge to control the direct VGA descendant.
-   So for every device we register, we need to iterate all its parent bridges
-   so we can invalidate any devices using them properly.
-*/
+/*
+ * Rules for using a bridge to control a VGA descendant decoding: if a bridge
+ * has only one VGA descendant then it can be used to control the VGA routing
+ * for that device. It should always use the bridge closest to the device to
+ * control it. If a bridge has a direct VGA descendant, but also have a sub-
+ * bridge VGA descendant then we cannot use that bridge to control the direct
+ * VGA descendant. So for every device we register, we need to iterate all
+ * its parent bridges so we can invalidate any devices using them properly.
+ */
 static void vga_arbiter_check_bridge_sharing(struct vga_device *vgadev)
 {
 	struct vga_device *same_bridge_vgadev;
@@ -484,21 +487,26 @@ static void vga_arbiter_check_bridge_sharing(struct vga_device *vgadev)
 
 			/* see if the share a bridge with this device */
 			if (new_bridge == bridge) {
-				/* if their direct parent bridge is the same
-				   as any bridge of this device then it can't be used
-				   for that device */
+				/*
+				 * If their direct parent bridge is the same
+				 * as any bridge of this device then it can't
+				 * be used for that device.
+				 */
 				same_bridge_vgadev->bridge_has_one_vga = false;
 			}
 
-			/* now iterate the previous devices bridge hierarchy */
-			/* if the new devices parent bridge is in the other devices
-			   hierarchy then we can't use it to control this device */
+			/*
+			 * Now iterate the previous devices bridge hierarchy.
+			 * If the new devices parent bridge is in the other
+			 * devices hierarchy then we can't use it to control
+			 * this device
+			 */
 			while (bus) {
 				bridge = bus->self;
-				if (bridge) {
-					if (bridge == vgadev->pdev->bus->self)
-						vgadev->bridge_has_one_vga = false;
-				}
+
+				if (bridge && bridge == vgadev->pdev->bus->self)
+					vgadev->bridge_has_one_vga = false;
+
 				bus = bus->parent;
 			}
 		}
@@ -525,18 +533,16 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev)
 		return false;
 
 	/* Allocate structure */
-	vgadev = kmalloc(sizeof(struct vga_device), GFP_KERNEL);
+	vgadev = kzalloc(sizeof(struct vga_device), GFP_KERNEL);
 	if (vgadev == NULL) {
-		pr_err("vgaarb: failed to allocate pci device\n");
-		/* What to do on allocation failure ? For now, let's
-		 * just do nothing, I'm not sure there is anything saner
-		 * to be done
+		pr_err("failed to allocate pci device\n");
+		/*
+		 * What to do on allocation failure ? For now, let's just do
+		 * nothing, I'm not sure there is anything saner to be done.
 		 */
 		return false;
 	}
 
-	memset(vgadev, 0, sizeof(*vgadev));
-
 	/* Take lock & check for duplicates */
 	spin_lock_irqsave(&vga_lock, flags);
 	if (vgadev_find(pdev) != NULL) {
@@ -566,8 +572,8 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev)
 		bridge = bus->self;
 		if (bridge) {
 			u16 l;
-			pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
-					     &l);
+
+			pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, &l);
 			if (!(l & PCI_BRIDGE_CTL_VGA)) {
 				vgadev->owns = 0;
 				break;
@@ -581,8 +587,7 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev)
 	 */
 	if (vga_default == NULL &&
 	    ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) {
-		pr_info("vgaarb: setting as boot device: PCI:%s\n",
-			pci_name(pdev));
+		pr_info("setting as boot device: PCI:%s\n", pci_name(pdev));
 		vga_set_default_device(pdev);
 	}
 
@@ -591,7 +596,7 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev)
 	/* Add to the list */
 	list_add(&vgadev->list, &vga_list);
 	vga_count++;
-	pr_info("vgaarb: device added: PCI:%s,decodes=%s,owns=%s,locks=%s\n",
+	pr_info("device added: PCI:%s,decodes=%s,owns=%s,locks=%s\n",
 		pci_name(pdev),
 		vga_iostate_to_str(vgadev->decodes),
 		vga_iostate_to_str(vgadev->owns),
@@ -651,7 +656,7 @@ static inline void vga_update_device_decodes(struct vga_device *vgadev,
 	decodes_unlocked = vgadev->locks & decodes_removed;
 	vgadev->decodes = new_decodes;
 
-	pr_info("vgaarb: device changed decodes: PCI:%s,olddecodes=%s,decodes=%s:owns=%s\n",
+	pr_info("device changed decodes: PCI:%s,olddecodes=%s,decodes=%s:owns=%s\n",
 		pci_name(vgadev->pdev),
 		vga_iostate_to_str(old_decodes),
 		vga_iostate_to_str(vgadev->decodes),
@@ -673,10 +678,12 @@ static inline void vga_update_device_decodes(struct vga_device *vgadev,
 	if (!(old_decodes & VGA_RSRC_LEGACY_MASK) &&
 	    new_decodes & VGA_RSRC_LEGACY_MASK)
 		vga_decode_count++;
-	pr_debug("vgaarb: decoding count now is: %d\n", vga_decode_count);
+	pr_debug("decoding count now is: %d\n", vga_decode_count);
 }
 
-static void __vga_set_legacy_decoding(struct pci_dev *pdev, unsigned int decodes, bool userspace)
+static void __vga_set_legacy_decoding(struct pci_dev *pdev,
+				      unsigned int decodes,
+				      bool userspace)
 {
 	struct vga_device *vgadev;
 	unsigned long flags;
@@ -712,7 +719,8 @@ EXPORT_SYMBOL(vga_set_legacy_decoding);
 /* call with NULL to unregister */
 int vga_client_register(struct pci_dev *pdev, void *cookie,
 			void (*irq_set_state)(void *cookie, bool state),
-			unsigned int (*set_vga_decode)(void *cookie, bool decode))
+			unsigned int (*set_vga_decode)(void *cookie,
+						       bool decode))
 {
 	int ret = -ENODEV;
 	struct vga_device *vgadev;
@@ -832,7 +840,7 @@ static int vga_pci_str_to_vars(char *buf, int count, unsigned int *domain,
 	return 1;
 }
 
-static ssize_t vga_arb_read(struct file *file, char __user * buf,
+static ssize_t vga_arb_read(struct file *file, char __user *buf,
 			    size_t count, loff_t *ppos)
 {
 	struct vga_arb_private *priv = file->private_data;
@@ -899,7 +907,7 @@ done:
  * TODO: To avoid parsing inside kernel and to improve the speed we may
  * consider use ioctl here
  */
-static ssize_t vga_arb_write(struct file *file, const char __user * buf,
+static ssize_t vga_arb_write(struct file *file, const char __user *buf,
 			     size_t count, loff_t *ppos)
 {
 	struct vga_arb_private *priv = file->private_data;
@@ -1075,13 +1083,13 @@ static ssize_t vga_arb_write(struct file *file, const char __user * buf,
 				ret_val = -EPROTO;
 				goto done;
 			}
-			pr_debug("vgaarb: %s ==> %x:%x:%x.%x\n", curr_pos,
+			pr_debug("%s ==> %x:%x:%x.%x\n", curr_pos,
 				domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
 
 			pdev = pci_get_domain_bus_and_slot(domain, bus, devfn);
-			pr_debug("vgaarb: pdev %p\n", pdev);
+			pr_debug("pdev %p\n", pdev);
 			if (!pdev) {
-				pr_err("vgaarb: invalid PCI address %x:%x:%x\n",
+				pr_err("invalid PCI address %x:%x:%x\n",
 					domain, bus, devfn);
 				ret_val = -ENODEV;
 				goto done;
@@ -1089,10 +1097,13 @@ static ssize_t vga_arb_write(struct file *file, const char __user * buf,
 		}
 
 		vgadev = vgadev_find(pdev);
-		pr_debug("vgaarb: vgadev %p\n", vgadev);
+		pr_debug("vgadev %p\n", vgadev);
 		if (vgadev == NULL) {
-			pr_err("vgaarb: this pci device is not a vga device\n");
-			pci_dev_put(pdev);
+			if (pdev) {
+				pr_err("this pci device is not a vga device\n");
+				pci_dev_put(pdev);
+			}
+
 			ret_val = -ENODEV;
 			goto done;
 		}
@@ -1109,7 +1120,7 @@ static ssize_t vga_arb_write(struct file *file, const char __user * buf,
 			}
 		}
 		if (i == MAX_USER_CARDS) {
-			pr_err("vgaarb: maximum user cards (%d) number reached!\n",
+			pr_err("maximum user cards (%d) number reached!\n",
 				MAX_USER_CARDS);
 			pci_dev_put(pdev);
 			/* XXX: which value to return? */
@@ -1125,7 +1136,7 @@ static ssize_t vga_arb_write(struct file *file, const char __user * buf,
 	} else if (strncmp(curr_pos, "decodes ", 8) == 0) {
 		curr_pos += 8;
 		remaining -= 8;
-		pr_debug("vgaarb: client 0x%p called 'decodes'\n", priv);
+		pr_debug("client 0x%p called 'decodes'\n", priv);
 
 		if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) {
 			ret_val = -EPROTO;
@@ -1150,7 +1161,7 @@ done:
 	return ret_val;
 }
 
-static unsigned int vga_arb_fpoll(struct file *file, poll_table * wait)
+static unsigned int vga_arb_fpoll(struct file *file, poll_table *wait)
 {
 	struct vga_arb_private *priv = file->private_data;
 
@@ -1246,7 +1257,8 @@ static void vga_arbiter_notify_clients(void)
 		else
 			new_state = true;
 		if (vgadev->set_vga_decode) {
-			new_decodes = vgadev->set_vga_decode(vgadev->cookie, new_state);
+			new_decodes = vgadev->set_vga_decode(vgadev->cookie,
+							     new_state);
 			vga_update_device_decodes(vgadev, new_decodes);
 		}
 	}
@@ -1300,7 +1312,7 @@ static int __init vga_arb_device_init(void)
 
 	rc = misc_register(&vga_arb_device);
 	if (rc < 0)
-		pr_err("vgaarb: error %d registering device\n", rc);
+		pr_err("error %d registering device\n", rc);
 
 	bus_register_notifier(&pci_bus_type, &pci_notifier);
 
@@ -1312,21 +1324,29 @@ static int __init vga_arb_device_init(void)
 			       PCI_ANY_ID, pdev)) != NULL)
 		vga_arbiter_add_pci_device(pdev);
 
-	pr_info("vgaarb: loaded\n");
+	pr_info("loaded\n");
 
 	list_for_each_entry(vgadev, &vga_list, list) {
 #if defined(CONFIG_X86) || defined(CONFIG_IA64)
-		/* Override I/O based detection done by vga_arbiter_add_pci_device()
-		 * as it may take the wrong device (e.g. on Apple system under EFI).
+		/*
+		 * Override vga_arbiter_add_pci_device()'s I/O based detection
+		 * as it may take the wrong device (e.g. on Apple system under
+		 * EFI).
 		 *
-		 * Select the device owning the boot framebuffer if there is one.
+		 * Select the device owning the boot framebuffer if there is
+		 * one.
 		 */
-		resource_size_t start, end;
+		resource_size_t start, end, limit;
+		unsigned long flags;
 		int i;
 
+		limit = screen_info.lfb_base + screen_info.lfb_size;
+
 		/* Does firmware framebuffer belong to us? */
 		for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
-			if (!(pci_resource_flags(vgadev->pdev, i) & IORESOURCE_MEM))
+			flags = pci_resource_flags(vgadev->pdev, i);
+
+			if ((flags & IORESOURCE_MEM) == 0)
 				continue;
 
 			start = pci_resource_start(vgadev->pdev, i);
@@ -1335,22 +1355,24 @@ static int __init vga_arb_device_init(void)
 			if (!start || !end)
 				continue;
 
-			if (screen_info.lfb_base < start ||
-			    (screen_info.lfb_base + screen_info.lfb_size) >= end)
+			if (screen_info.lfb_base < start || limit >= end)
 				continue;
+
 			if (!vga_default_device())
-				pr_info("vgaarb: setting as boot device: PCI:%s\n",
+				pr_info("setting as boot device: PCI:%s\n",
 					pci_name(vgadev->pdev));
 			else if (vgadev->pdev != vga_default_device())
-				pr_info("vgaarb: overriding boot device: PCI:%s\n",
+				pr_info("overriding boot device: PCI:%s\n",
 					pci_name(vgadev->pdev));
 			vga_set_default_device(vgadev->pdev);
 		}
 #endif
 		if (vgadev->bridge_has_one_vga)
-			pr_info("vgaarb: bridge control possible %s\n", pci_name(vgadev->pdev));
+			pr_info("bridge control possible %s\n",
+				pci_name(vgadev->pdev));
 		else
-			pr_info("vgaarb: no bridge control possible %s\n", pci_name(vgadev->pdev));
+			pr_info("no bridge control possible %s\n",
+				pci_name(vgadev->pdev));
 	}
 	return rc;
 }