Merge tag 'ib-mfd-regulator-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd into regulator-tps65090

Immutable branch between MFD and Regulator due for v3.16 merge-window.

49 files changed, 1044 insertions, 912 deletions

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 9d25dbbe677..48e38ba2278 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -23,7 +23,7 @@ drm-$(CONFIG_DRM_PANEL) += drm_panel.o
 
 drm-usb-y   := drm_usb.o
 
-drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o
+drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o
 drm_kms_helper-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
 drm_kms_helper-$(CONFIG_DRM_KMS_FB_HELPER) += drm_fb_helper.o
 drm_kms_helper-$(CONFIG_DRM_KMS_CMA_HELPER) += drm_fb_cma_helper.o
diff --git a/drivers/gpu/drm/ast/ast_post.c b/drivers/gpu/drm/ast/ast_post.c
index 977cfb35837..635f6ffc27c 100644
--- a/drivers/gpu/drm/ast/ast_post.c
+++ b/drivers/gpu/drm/ast/ast_post.c
@@ -572,7 +572,7 @@ static u32 cbr_scan2(struct ast_private *ast)
 		for (loop = 0; loop < CBR_PASSNUM2; loop++) {
 			if ((data = cbr_test2(ast)) != 0) {
 				data2 &= data;
-				if (!data)
+				if (!data2)
 					return 0;
 				break;
 			}
diff --git a/drivers/gpu/drm/bochs/bochs.h b/drivers/gpu/drm/bochs/bochs.h
index 741965c001a..7eb52dd44b0 100644
--- a/drivers/gpu/drm/bochs/bochs.h
+++ b/drivers/gpu/drm/bochs/bochs.h
@@ -1,5 +1,6 @@
 #include <linux/io.h>
 #include <linux/fb.h>
+#include <linux/console.h>
 
 #include <drm/drmP.h>
 #include <drm/drm_crtc.h>
@@ -87,8 +88,6 @@ struct bochs_device {
 		struct bochs_framebuffer gfb;
 		struct drm_fb_helper helper;
 		int size;
-		int x1, y1, x2, y2; /* dirty rect */
-		spinlock_t dirty_lock;
 		bool initialized;
 	} fb;
 };
diff --git a/drivers/gpu/drm/bochs/bochs_drv.c b/drivers/gpu/drm/bochs/bochs_drv.c
index 395bba261c9..9c13df29fd2 100644
--- a/drivers/gpu/drm/bochs/bochs_drv.c
+++ b/drivers/gpu/drm/bochs/bochs_drv.c
@@ -95,6 +95,49 @@ static struct drm_driver bochs_driver = {
 };
 
 /* ---------------------------------------------------------------------- */
+/* pm interface                                                           */
+
+static int bochs_pm_suspend(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct drm_device *drm_dev = pci_get_drvdata(pdev);
+	struct bochs_device *bochs = drm_dev->dev_private;
+
+	drm_kms_helper_poll_disable(drm_dev);
+
+	if (bochs->fb.initialized) {
+		console_lock();
+		fb_set_suspend(bochs->fb.helper.fbdev, 1);
+		console_unlock();
+	}
+
+	return 0;
+}
+
+static int bochs_pm_resume(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct drm_device *drm_dev = pci_get_drvdata(pdev);
+	struct bochs_device *bochs = drm_dev->dev_private;
+
+	drm_helper_resume_force_mode(drm_dev);
+
+	if (bochs->fb.initialized) {
+		console_lock();
+		fb_set_suspend(bochs->fb.helper.fbdev, 0);
+		console_unlock();
+	}
+
+	drm_kms_helper_poll_enable(drm_dev);
+	return 0;
+}
+
+static const struct dev_pm_ops bochs_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(bochs_pm_suspend,
+				bochs_pm_resume)
+};
+
+/* ---------------------------------------------------------------------- */
 /* pci interface                                                          */
 
 static int bochs_kick_out_firmware_fb(struct pci_dev *pdev)
@@ -155,6 +198,7 @@ static struct pci_driver bochs_pci_driver = {
 	.id_table =	bochs_pci_tbl,
 	.probe =	bochs_pci_probe,
 	.remove =	bochs_pci_remove,
+	.driver.pm =    &bochs_pm_ops,
 };
 
 /* ---------------------------------------------------------------------- */
diff --git a/drivers/gpu/drm/bochs/bochs_fbdev.c b/drivers/gpu/drm/bochs/bochs_fbdev.c
index 4da5206b7cc..561b8447412 100644
--- a/drivers/gpu/drm/bochs/bochs_fbdev.c
+++ b/drivers/gpu/drm/bochs/bochs_fbdev.c
@@ -190,7 +190,6 @@ int bochs_fbdev_init(struct bochs_device *bochs)
 	int ret;
 
 	bochs->fb.helper.funcs = &bochs_fb_helper_funcs;
-	spin_lock_init(&bochs->fb.dirty_lock);
 
 	ret = drm_fb_helper_init(bochs->dev, &bochs->fb.helper,
 				 1, 1);
diff --git a/drivers/gpu/drm/cirrus/cirrus_drv.c b/drivers/gpu/drm/cirrus/cirrus_drv.c
index 953fc8aea69..08ce520f61a 100644
--- a/drivers/gpu/drm/cirrus/cirrus_drv.c
+++ b/drivers/gpu/drm/cirrus/cirrus_drv.c
@@ -11,6 +11,7 @@
 #include <linux/module.h>
 #include <linux/console.h>
 #include <drm/drmP.h>
+#include <drm/drm_crtc_helper.h>
 
 #include "cirrus_drv.h"
 
@@ -75,6 +76,41 @@ static void cirrus_pci_remove(struct pci_dev *pdev)
 	drm_put_dev(dev);
 }
 
+static int cirrus_pm_suspend(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct drm_device *drm_dev = pci_get_drvdata(pdev);
+	struct cirrus_device *cdev = drm_dev->dev_private;
+
+	drm_kms_helper_poll_disable(drm_dev);
+
+	if (cdev->mode_info.gfbdev) {
+		console_lock();
+		fb_set_suspend(cdev->mode_info.gfbdev->helper.fbdev, 1);
+		console_unlock();
+	}
+
+	return 0;
+}
+
+static int cirrus_pm_resume(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct drm_device *drm_dev = pci_get_drvdata(pdev);
+	struct cirrus_device *cdev = drm_dev->dev_private;
+
+	drm_helper_resume_force_mode(drm_dev);
+
+	if (cdev->mode_info.gfbdev) {
+		console_lock();
+		fb_set_suspend(cdev->mode_info.gfbdev->helper.fbdev, 0);
+		console_unlock();
+	}
+
+	drm_kms_helper_poll_enable(drm_dev);
+	return 0;
+}
+
 static const struct file_operations cirrus_driver_fops = {
 	.owner = THIS_MODULE,
 	.open = drm_open,
@@ -103,11 +139,17 @@ static struct drm_driver driver = {
 	.dumb_destroy = drm_gem_dumb_destroy,
 };
 
+static const struct dev_pm_ops cirrus_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(cirrus_pm_suspend,
+				cirrus_pm_resume)
+};
+
 static struct pci_driver cirrus_pci_driver = {
 	.name = DRIVER_NAME,
 	.id_table = pciidlist,
 	.probe = cirrus_pci_probe,
 	.remove = cirrus_pci_remove,
+	.driver.pm = &cirrus_pm_ops,
 };
 
 static int __init cirrus_init(void)
diff --git a/drivers/gpu/drm/cirrus/cirrus_mode.c b/drivers/gpu/drm/cirrus/cirrus_mode.c
index 2d64aea83df..f59433b7610 100644
--- a/drivers/gpu/drm/cirrus/cirrus_mode.c
+++ b/drivers/gpu/drm/cirrus/cirrus_mode.c
@@ -308,6 +308,9 @@ static int cirrus_crtc_mode_set(struct drm_crtc *crtc,
 
 	WREG_HDR(hdr);
 	cirrus_crtc_do_set_base(crtc, old_fb, x, y, 0);
+
+	/* Unblank (needed on S3 resume, vgabios doesn't do it then) */
+	outb(0x20, 0x3c0);
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index c43825e8f5c..df281b54db0 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -72,147 +72,6 @@ void drm_helper_move_panel_connectors_to_head(struct drm_device *dev)
 }
 EXPORT_SYMBOL(drm_helper_move_panel_connectors_to_head);
 
-static bool drm_kms_helper_poll = true;
-module_param_named(poll, drm_kms_helper_poll, bool, 0600);
-
-static void drm_mode_validate_flag(struct drm_connector *connector,
-				   int flags)
-{
-	struct drm_display_mode *mode;
-
-	if (flags == (DRM_MODE_FLAG_DBLSCAN | DRM_MODE_FLAG_INTERLACE |
-		      DRM_MODE_FLAG_3D_MASK))
-		return;
-
-	list_for_each_entry(mode, &connector->modes, head) {
-		if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
-				!(flags & DRM_MODE_FLAG_INTERLACE))
-			mode->status = MODE_NO_INTERLACE;
-		if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
-				!(flags & DRM_MODE_FLAG_DBLSCAN))
-			mode->status = MODE_NO_DBLESCAN;
-		if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
-				!(flags & DRM_MODE_FLAG_3D_MASK))
-			mode->status = MODE_NO_STEREO;
-	}
-
-	return;
-}
-
-/**
- * drm_helper_probe_single_connector_modes - get complete set of display modes
- * @connector: connector to probe
- * @maxX: max width for modes
- * @maxY: max height for modes
- *
- * Based on the helper callbacks implemented by @connector try to detect all
- * valid modes.  Modes will first be added to the connector's probed_modes list,
- * then culled (based on validity and the @maxX, @maxY parameters) and put into
- * the normal modes list.
- *
- * Intended to be use as a generic implementation of the ->fill_modes()
- * @connector vfunc for drivers that use the crtc helpers for output mode
- * filtering and detection.
- *
- * Returns:
- * The number of modes found on @connector.
- */
-int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
-					    uint32_t maxX, uint32_t maxY)
-{
-	struct drm_device *dev = connector->dev;
-	struct drm_display_mode *mode;
-	struct drm_connector_helper_funcs *connector_funcs =
-		connector->helper_private;
-	int count = 0;
-	int mode_flags = 0;
-	bool verbose_prune = true;
-
-	WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
-
-	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
-			drm_get_connector_name(connector));
-	/* set all modes to the unverified state */
-	list_for_each_entry(mode, &connector->modes, head)
-		mode->status = MODE_UNVERIFIED;
-
-	if (connector->force) {
-		if (connector->force == DRM_FORCE_ON)
-			connector->status = connector_status_connected;
-		else
-			connector->status = connector_status_disconnected;
-		if (connector->funcs->force)
-			connector->funcs->force(connector);
-	} else {
-		connector->status = connector->funcs->detect(connector, true);
-	}
-
-	/* Re-enable polling in case the global poll config changed. */
-	if (drm_kms_helper_poll != dev->mode_config.poll_running)
-		drm_kms_helper_poll_enable(dev);
-
-	dev->mode_config.poll_running = drm_kms_helper_poll;
-
-	if (connector->status == connector_status_disconnected) {
-		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
-			connector->base.id, drm_get_connector_name(connector));
-		drm_mode_connector_update_edid_property(connector, NULL);
-		verbose_prune = false;
-		goto prune;
-	}
-
-#ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
-	count = drm_load_edid_firmware(connector);
-	if (count == 0)
-#endif
-		count = (*connector_funcs->get_modes)(connector);
-
-	if (count == 0 && connector->status == connector_status_connected)
-		count = drm_add_modes_noedid(connector, 1024, 768);
-	if (count == 0)
-		goto prune;
-
-	drm_mode_connector_list_update(connector);
-
-	if (maxX && maxY)
-		drm_mode_validate_size(dev, &connector->modes, maxX, maxY);
-
-	if (connector->interlace_allowed)
-		mode_flags |= DRM_MODE_FLAG_INTERLACE;
-	if (connector->doublescan_allowed)
-		mode_flags |= DRM_MODE_FLAG_DBLSCAN;
-	if (connector->stereo_allowed)
-		mode_flags |= DRM_MODE_FLAG_3D_MASK;
-	drm_mode_validate_flag(connector, mode_flags);
-
-	list_for_each_entry(mode, &connector->modes, head) {
-		if (mode->status == MODE_OK)
-			mode->status = connector_funcs->mode_valid(connector,
-								   mode);
-	}
-
-prune:
-	drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
-
-	if (list_empty(&connector->modes))
-		return 0;
-
-	list_for_each_entry(mode, &connector->modes, head)
-		mode->vrefresh = drm_mode_vrefresh(mode);
-
-	drm_mode_sort(&connector->modes);
-
-	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
-			drm_get_connector_name(connector));
-	list_for_each_entry(mode, &connector->modes, head) {
-		drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
-		drm_mode_debug_printmodeline(mode);
-	}
-
-	return count;
-}
-EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
-
 /**
  * drm_helper_encoder_in_use - check if a given encoder is in use
  * @encoder: encoder to check
@@ -1020,232 +879,3 @@ void drm_helper_resume_force_mode(struct drm_device *dev)
 	drm_modeset_unlock_all(dev);
 }
 EXPORT_SYMBOL(drm_helper_resume_force_mode);
-
-/**
- * drm_kms_helper_hotplug_event - fire off KMS hotplug events
- * @dev: drm_device whose connector state changed
- *
- * This function fires off the uevent for userspace and also calls the
- * output_poll_changed function, which is most commonly used to inform the fbdev
- * emulation code and allow it to update the fbcon output configuration.
- *
- * Drivers should call this from their hotplug handling code when a change is
- * detected. Note that this function does not do any output detection of its
- * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
- * driver already.
- *
- * This function must be called from process context with no mode
- * setting locks held.
- */
-void drm_kms_helper_hotplug_event(struct drm_device *dev)
-{
-	/* send a uevent + call fbdev */
-	drm_sysfs_hotplug_event(dev);
-	if (dev->mode_config.funcs->output_poll_changed)
-		dev->mode_config.funcs->output_poll_changed(dev);
-}
-EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
-
-#define DRM_OUTPUT_POLL_PERIOD (10*HZ)
-static void output_poll_execute(struct work_struct *work)
-{
-	struct delayed_work *delayed_work = to_delayed_work(work);
-	struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
-	struct drm_connector *connector;
-	enum drm_connector_status old_status;
-	bool repoll = false, changed = false;
-
-	if (!drm_kms_helper_poll)
-		return;
-
-	mutex_lock(&dev->mode_config.mutex);
-	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
-
-		/* Ignore forced connectors. */
-		if (connector->force)
-			continue;
-
-		/* Ignore HPD capable connectors and connectors where we don't
-		 * want any hotplug detection at all for polling. */
-		if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
-			continue;
-
-		repoll = true;
-
-		old_status = connector->status;
-		/* if we are connected and don't want to poll for disconnect
-		   skip it */
-		if (old_status == connector_status_connected &&
-		    !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
-			continue;
-
-		connector->status = connector->funcs->detect(connector, false);
-		if (old_status != connector->status) {
-			const char *old, *new;
-
-			old = drm_get_connector_status_name(old_status);
-			new = drm_get_connector_status_name(connector->status);
-
-			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
-				      "status updated from %s to %s\n",
-				      connector->base.id,
-				      drm_get_connector_name(connector),
-				      old, new);
-
-			changed = true;
-		}
-	}
-
-	mutex_unlock(&dev->mode_config.mutex);
-
-	if (changed)
-		drm_kms_helper_hotplug_event(dev);
-
-	if (repoll)
-		schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
-}
-
-/**
- * drm_kms_helper_poll_disable - disable output polling
- * @dev: drm_device
- *
- * This function disables the output polling work.
- *
- * Drivers can call this helper from their device suspend implementation. It is
- * not an error to call this even when output polling isn't enabled or arlready
- * disabled.
- */
-void drm_kms_helper_poll_disable(struct drm_device *dev)
-{
-	if (!dev->mode_config.poll_enabled)
-		return;
-	cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
-}
-EXPORT_SYMBOL(drm_kms_helper_poll_disable);
-
-/**
- * drm_kms_helper_poll_enable - re-enable output polling.
- * @dev: drm_device
- *
- * This function re-enables the output polling work.
- *
- * Drivers can call this helper from their device resume implementation. It is
- * an error to call this when the output polling support has not yet been set
- * up.
- */
-void drm_kms_helper_poll_enable(struct drm_device *dev)
-{
-	bool poll = false;
-	struct drm_connector *connector;
-
-	if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
-		return;
-
-	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
-		if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
-					 DRM_CONNECTOR_POLL_DISCONNECT))
-			poll = true;
-	}
-
-	if (poll)
-		schedule_delayed_work(&dev->mode_config.output_poll_work, DRM_OUTPUT_POLL_PERIOD);
-}
-EXPORT_SYMBOL(drm_kms_helper_poll_enable);
-
-/**
- * drm_kms_helper_poll_init - initialize and enable output polling
- * @dev: drm_device
- *
- * This function intializes and then also enables output polling support for
- * @dev. Drivers which do not have reliable hotplug support in hardware can use
- * this helper infrastructure to regularly poll such connectors for changes in
- * their connection state.
- *
- * Drivers can control which connectors are polled by setting the
- * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
- * connectors where probing live outputs can result in visual distortion drivers
- * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
- * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
- * completely ignored by the polling logic.
- *
- * Note that a connector can be both polled and probed from the hotplug handler,
- * in case the hotplug interrupt is known to be unreliable.
- */
-void drm_kms_helper_poll_init(struct drm_device *dev)
-{
-	INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
-	dev->mode_config.poll_enabled = true;
-
-	drm_kms_helper_poll_enable(dev);
-}
-EXPORT_SYMBOL(drm_kms_helper_poll_init);
-
-/**
- * drm_kms_helper_poll_fini - disable output polling and clean it up
- * @dev: drm_device
- */
-void drm_kms_helper_poll_fini(struct drm_device *dev)
-{
-	drm_kms_helper_poll_disable(dev);
-}
-EXPORT_SYMBOL(drm_kms_helper_poll_fini);
-
-/**
- * drm_helper_hpd_irq_event - hotplug processing
- * @dev: drm_device
- *
- * Drivers can use this helper function to run a detect cycle on all connectors
- * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
- * other connectors are ignored, which is useful to avoid reprobing fixed
- * panels.
- *
- * This helper function is useful for drivers which can't or don't track hotplug
- * interrupts for each connector.
- *
- * Drivers which support hotplug interrupts for each connector individually and
- * which have a more fine-grained detect logic should bypass this code and
- * directly call drm_kms_helper_hotplug_event() in case the connector state
- * changed.
- *
- * This function must be called from process context with no mode
- * setting locks held.
- *
- * Note that a connector can be both polled and probed from the hotplug handler,
- * in case the hotplug interrupt is known to be unreliable.
- */
-bool drm_helper_hpd_irq_event(struct drm_device *dev)
-{
-	struct drm_connector *connector;
-	enum drm_connector_status old_status;
-	bool changed = false;
-
-	if (!dev->mode_config.poll_enabled)
-		return false;
-
-	mutex_lock(&dev->mode_config.mutex);
-	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
-
-		/* Only handle HPD capable connectors. */
-		if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
-			continue;
-
-		old_status = connector->status;
-
-		connector->status = connector->funcs->detect(connector, false);
-		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
-			      connector->base.id,
-			      drm_get_connector_name(connector),
-			      drm_get_connector_status_name(old_status),
-			      drm_get_connector_status_name(connector->status));
-		if (old_status != connector->status)
-			changed = true;
-	}
-
-	mutex_unlock(&dev->mode_config.mutex);
-
-	if (changed)
-		drm_kms_helper_hotplug_event(dev);
-
-	return changed;
-}
-EXPORT_SYMBOL(drm_helper_hpd_irq_event);
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 27671489477..4b6e6f3ba0a 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -577,7 +577,9 @@ static u32 drm_dp_i2c_functionality(struct i2c_adapter *adapter)
 
 /*
  * Transfer a single I2C-over-AUX message and handle various error conditions,
- * retrying the transaction as appropriate.
+ * retrying the transaction as appropriate.  It is assumed that the
+ * aux->transfer function does not modify anything in the msg other than the
+ * reply field.
  */
 static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
 {
@@ -665,11 +667,26 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
 {
 	struct drm_dp_aux *aux = adapter->algo_data;
 	unsigned int i, j;
+	struct drm_dp_aux_msg msg;
+	int err = 0;
 
-	for (i = 0; i < num; i++) {
-		struct drm_dp_aux_msg msg;
-		int err;
+	memset(&msg, 0, sizeof(msg));
 
+	for (i = 0; i < num; i++) {
+		msg.address = msgs[i].addr;
+		msg.request = (msgs[i].flags & I2C_M_RD) ?
+			DP_AUX_I2C_READ :
+			DP_AUX_I2C_WRITE;
+		msg.request |= DP_AUX_I2C_MOT;
+		/* Send a bare address packet to start the transaction.
+		 * Zero sized messages specify an address only (bare
+		 * address) transaction.
+		 */
+		msg.buffer = NULL;
+		msg.size = 0;
+		err = drm_dp_i2c_do_msg(aux, &msg);
+		if (err < 0)
+			break;
 		/*
 		 * Many hardware implementations support FIFOs larger than a
 		 * single byte, but it has been empirically determined that
@@ -678,30 +695,28 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
 		 * transferred byte-by-byte.
 		 */
 		for (j = 0; j < msgs[i].len; j++) {
-			memset(&msg, 0, sizeof(msg));
-			msg.address = msgs[i].addr;
-
-			msg.request = (msgs[i].flags & I2C_M_RD) ?
-					DP_AUX_I2C_READ :
-					DP_AUX_I2C_WRITE;
-
-			/*
-			 * All messages except the last one are middle-of-
-			 * transfer messages.
-			 */
-			if ((i < num - 1) || (j < msgs[i].len - 1))
-				msg.request |= DP_AUX_I2C_MOT;
-
 			msg.buffer = msgs[i].buf + j;
 			msg.size = 1;
 
 			err = drm_dp_i2c_do_msg(aux, &msg);
 			if (err < 0)
-				return err;
+				break;
 		}
+		if (err < 0)
+			break;
 	}
+	if (err >= 0)
+		err = num;
+	/* Send a bare address packet to close out the transaction.
+	 * Zero sized messages specify an address only (bare
+	 * address) transaction.
+	 */
+	msg.request &= ~DP_AUX_I2C_MOT;
+	msg.buffer = NULL;
+	msg.size = 0;
+	(void)drm_dp_i2c_do_msg(aux, &msg);
 
-	return num;
+	return err;
 }
 
 static const struct i2c_algorithm drm_dp_i2c_algo = {
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm