Merge tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging and IIO updates from Greg KH:
 "Here is the big staging and IIO driver pull request for 4.9-rc1.

  There are a lot of patches in here, the majority due to the
  drivers/staging/greybus/ subsystem being merged in with full
  development history that went back a few years, in order to preserve
  the work that those developers did over time.

  Lots and lots of tiny cleanups happened in the tree as well, due to
  the Outreachy application process and lots of other developers showing
  up for the first time to clean code up.  Along with those changes, we
  deleted a wireless driver, and added a raspberrypi driver (currently
  marked broken), and lots of new iio drivers.

  Overall the tree still shrunk with more lines removed than added,
  about 10 thousand lines removed in total. Full details are in the very
  long shortlog below.

  All of this has been in the linux-next tree with no issues. There will
  be some merge problems with other subsystem trees, but those are all
  minor problems and shouldn't be hard to work out when they happen
  (MAINTAINERS and some lustre build problems with the IB tree)"

And furter from me asking for clarification about greybus:
 "Right now there is a phone from Motorola shipping with this code (a
  slightly older version, but the same tree), so even though Ara is not
  alive in the same form, the functionality is happening. We are working
  with the developers of that phone to merge the newer stuff in with
  their fork so they can use the upstream version in future versions of
  their phone product line.

  Toshiba has at least one chip shipping in their catalog that
  needs/uses this protocol over a Unipro link, and rumor has it that
  there might be more in the future.

  There are also other users of the greybus protocols, there is a talk
  next week at ELC that shows how it is being used across a network
  connection to control a device, and previous ELC talks have showed the
  protocol stack being used over USB to drive embedded Linux boards.
  I've also talked to some people who are starting to work to add a host
  controller driver to control arduinos as the greybus PHY protocols are
  very useful to control a serial/i2c/spio/whatever device across a
  random physical link, as it is a way to have a self-describing device
  be attached to a host without needing manual configuration.

  So yes, people are using it, and there is still the chance that it
  will show up in a phone/laptop/tablet/whatever from Google in the
  future as well, the tech isn't dead, even if the original large phone
  project happens to be"

* tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (3703 commits)
  Staging: fbtft: Fix bug in fbtft-core
  staging: rtl8188eu: fix double unlock error in rtw_resume_process()
  staging:r8188eu: remove GEN_MLME_EXT_HANDLER macro
  staging:r8188eu: remove GEN_DRV_CMD_HANDLER macro
  staging:r8188eu: remove GEN_EVT_CODE macro
  staging:r8188eu: remove GEN_CMD_CODE macro
  staging:r8188eu: remove pkt_newalloc member of the recv_buf structure
  staging:r8188eu: remove rtw_handle_dualmac declaration
  staging:r8188eu: remove (RGTRY|BSSID)_(OFT|SZ) macros
  staging:r8188eu: change rtl8188e_process_phy_info function argument type
  Staging: fsl-mc: Remove blank lines
  Staging: fsl-mc: Fix unaligned * in block comments
  Staging: comedi: Align the * in block comments
  Staging : ks7010 : Fix block comments warninig
  Staging: vt6655: Remove explicit NULL comparison using Coccinelle
  staging: rtl8188eu: core: rtw_xmit: Use macros instead of constants
  staging: rtl8188eu: core: rtw_xmit: Move constant of the right side
  staging: dgnc: Fix lines longer than 80 characters
  Staging: dgnc: constify attribute_group structures
  Staging: most: hdm-dim2: constify attribute_group structures
  ...

1 files changed, 103 insertions, 46 deletions

diff --git a/drivers/staging/unisys/visorinput/visorinput.c b/drivers/staging/unisys/visorinput/visorinput.c
index d67cd763..6f94b64 100644
--- a/drivers/staging/unisys/visorinput/visorinput.c
+++ b/drivers/staging/unisys/visorinput/visorinput.c
@@ -29,9 +29,7 @@
 #include <linux/kernel.h>
 #include <linux/uuid.h>
 
-#include "version.h"
 #include "visorbus.h"
-#include "channel.h"
 #include "ultrainputreport.h"
 
 /* Keyboard channel {c73416d0-b0b8-44af-b304-9d2ae99f1b3d} */
@@ -63,9 +61,10 @@ enum visorinput_device_type {
  */
 struct visorinput_devdata {
 	struct visor_device *dev;
-	struct rw_semaphore lock_visor_dev; /* lock for dev */
+	struct mutex lock_visor_dev; /* lock for dev */
 	struct input_dev *visorinput_dev;
 	bool paused;
+	bool interrupts_enabled;
 	unsigned int keycode_table_bytes; /* size of following array */
 	/* for keyboard devices: visorkbd_keycode[] + visorkbd_ext_keycode[] */
 	unsigned char keycode_table[0];
@@ -228,7 +227,21 @@ static int visorinput_open(struct input_dev *visorinput_dev)
 		return -EINVAL;
 	}
 	dev_dbg(&visorinput_dev->dev, "%s opened\n", __func__);
+
+	/*
+	 * If we're not paused, really enable interrupts.
+	 * Regardless of whether we are paused, set a flag indicating
+	 * interrupts should be enabled so when we resume, interrupts
+	 * will really be enabled.
+	 */
+	mutex_lock(&devdata->lock_visor_dev);
+	devdata->interrupts_enabled = true;
+	if (devdata->paused)
+		goto out_unlock;
 	visorbus_enable_channel_interrupts(devdata->dev);
+
+out_unlock:
+	mutex_unlock(&devdata->lock_visor_dev);
 	return 0;
 }
 
@@ -243,20 +256,35 @@ static void visorinput_close(struct input_dev *visorinput_dev)
 		return;
 	}
 	dev_dbg(&visorinput_dev->dev, "%s closed\n", __func__);
+
+	/*
+	 * If we're not paused, really disable interrupts.
+	 * Regardless of whether we are paused, set a flag indicating
+	 * interrupts should be disabled so when we resume we will
+	 * not re-enable them.
+	 */
+
+	mutex_lock(&devdata->lock_visor_dev);
+	devdata->interrupts_enabled = false;
+	if (devdata->paused)
+		goto out_unlock;
 	visorbus_disable_channel_interrupts(devdata->dev);
+
+out_unlock:
+	mutex_unlock(&devdata->lock_visor_dev);
 }
 
 /*
- * register_client_keyboard() initializes and returns a Linux input node that
+ * setup_client_keyboard() initializes and returns a Linux input node that
  * we can use to deliver keyboard inputs to Linux.  We of course do this when
  * we see keyboard inputs coming in on a keyboard channel.
  */
 static struct input_dev *
-register_client_keyboard(void *devdata,  /* opaque on purpose */
-			 unsigned char *keycode_table)
+setup_client_keyboard(void *devdata,  /* opaque on purpose */
+		      unsigned char *keycode_table)
 
 {
-	int i, error;
+	int i;
 	struct input_dev *visorinput_dev;
 
 	visorinput_dev = input_allocate_device();
@@ -290,18 +318,12 @@ register_client_keyboard(void *devdata,  /* opaque on purpose */
 	visorinput_dev->close = visorinput_close;
 	input_set_drvdata(visorinput_dev, devdata); /* pre input_register! */
 
-	error = input_register_device(visorinput_dev);
-	if (error) {
-		input_free_device(visorinput_dev);
-		return NULL;
-	}
 	return visorinput_dev;
 }
 
 static struct input_dev *
-register_client_mouse(void *devdata /* opaque on purpose */)
+setup_client_mouse(void *devdata /* opaque on purpose */)
 {
-	int error;
 	struct input_dev *visorinput_dev = NULL;
 	int xres, yres;
 	struct fb_info *fb0;
@@ -336,13 +358,6 @@ register_client_mouse(void *devdata /* opaque on purpose */)
 	visorinput_dev->open = visorinput_open;
 	visorinput_dev->close = visorinput_close;
 	input_set_drvdata(visorinput_dev, devdata); /* pre input_register! */
-
-	error = input_register_device(visorinput_dev);
-	if (error) {
-		input_free_device(visorinput_dev);
-		return NULL;
-	}
-
 	input_set_capability(visorinput_dev, EV_REL, REL_WHEEL);
 
 	return visorinput_dev;
@@ -360,9 +375,19 @@ devdata_create(struct visor_device *dev, enum visorinput_device_type devtype)
 	devdata = kzalloc(sizeof(*devdata) + extra_bytes, GFP_KERNEL);
 	if (!devdata)
 		return NULL;
+	mutex_init(&devdata->lock_visor_dev);
+	mutex_lock(&devdata->lock_visor_dev);
 	devdata->dev = dev;
 
 	/*
+	 * visorinput_open() can be called as soon as input_register_device()
+	 * happens, and that will enable channel interrupts.  Setting paused
+	 * prevents us from getting into visorinput_channel_interrupt() prior
+	 * to the device structure being totally initialized.
+	 */
+	devdata->paused = true;
+
+	/*
 	 * This is an input device in a client guest partition,
 	 * so we need to create whatever input nodes are necessary to
 	 * deliver our inputs to the guest OS.
@@ -374,23 +399,49 @@ devdata_create(struct visor_device *dev, enum visorinput_device_type devtype)
 		       KEYCODE_TABLE_BYTES);
 		memcpy(devdata->keycode_table + KEYCODE_TABLE_BYTES,
 		       visorkbd_ext_keycode, KEYCODE_TABLE_BYTES);
-		devdata->visorinput_dev = register_client_keyboard
+		devdata->visorinput_dev = setup_client_keyboard
 			(devdata, devdata->keycode_table);
 		if (!devdata->visorinput_dev)
 			goto cleanups_register;
 		break;
 	case visorinput_mouse:
-		devdata->visorinput_dev = register_client_mouse(devdata);
+		devdata->visorinput_dev = setup_client_mouse(devdata);
 		if (!devdata->visorinput_dev)
 			goto cleanups_register;
 		break;
 	}
 
-	init_rwsem(&devdata->lock_visor_dev);
+	dev_set_drvdata(&dev->device, devdata);
+	mutex_unlock(&devdata->lock_visor_dev);
+
+	/*
+	 * Device struct is completely set up now, with the exception of
+	 * visorinput_dev being registered.
+	 * We need to unlock before we register the device, because this
+	 * can cause an on-stack call of visorinput_open(), which would
+	 * deadlock if we had the lock.
+	 */
+	if (input_register_device(devdata->visorinput_dev)) {
+		input_free_device(devdata->visorinput_dev);
+		goto err_kfree_devdata;
+	}
+
+	mutex_lock(&devdata->lock_visor_dev);
+	/*
+	 * Establish calls to visorinput_channel_interrupt() if that is
+	 * the desired state that we've kept track of in interrupts_enabled
+	 * while the device was being created.
+	 */
+	devdata->paused = false;
+	if (devdata->interrupts_enabled)
+		visorbus_enable_channel_interrupts(dev);
+	mutex_unlock(&devdata->lock_visor_dev);
 
 	return devdata;
 
 cleanups_register:
+	mutex_unlock(&devdata->lock_visor_dev);
+err_kfree_devdata:
 	kfree(devdata);
 	return NULL;
 }
@@ -398,7 +449,6 @@ cleanups_register:
 static int
 visorinput_probe(struct visor_device *dev)
 {
-	struct visorinput_devdata *devdata = NULL;
 	uuid_le guid;
 	enum visorinput_device_type devtype;
 
@@ -409,10 +459,9 @@ visorinput_probe(struct visor_device *dev)
 		devtype = visorinput_keyboard;
 	else
 		return -ENODEV;
-	devdata = devdata_create(dev, devtype);
-	if (!devdata)
+	visorbus_disable_channel_interrupts(dev);
+	if (!devdata_create(dev, devtype))
 		return -ENOMEM;
-	dev_set_drvdata(&dev->device, devdata);
 	return 0;
 }
 
@@ -431,6 +480,7 @@ visorinput_remove(struct visor_device *dev)
 	if (!devdata)
 		return;
 
+	mutex_lock(&devdata->lock_visor_dev);
 	visorbus_disable_channel_interrupts(dev);
 
 	/*
@@ -438,10 +488,10 @@ visorinput_remove(struct visor_device *dev)
 	 * in visorinput_channel_interrupt()
 	 */
 
-	down_write(&devdata->lock_visor_dev);
 	dev_set_drvdata(&dev->device, NULL);
+	mutex_unlock(&devdata->lock_visor_dev);
+
 	unregister_client_input(devdata->visorinput_dev);
-	up_write(&devdata->lock_visor_dev);
 	kfree(devdata);
 }
 
@@ -529,15 +579,9 @@ visorinput_channel_interrupt(struct visor_device *dev)
 	if (!devdata)
 		return;
 
-	down_write(&devdata->lock_visor_dev);
-	if (devdata->paused) /* don't touch device/channel when paused */
-		goto out_locked;
-
 	visorinput_dev = devdata->visorinput_dev;
-	if (!visorinput_dev)
-		goto out_locked;
 
-	while (visorchannel_signalremove(dev->visorchannel, 0, &r)) {
+	while (!visorchannel_signalremove(dev->visorchannel, 0, &r)) {
 		scancode = r.activity.arg1;
 		keycode = scancode_to_keycode(scancode);
 		switch (r.activity.action) {
@@ -611,8 +655,6 @@ visorinput_channel_interrupt(struct visor_device *dev)
 			break;
 		}
 	}
-out_locked:
-	up_write(&devdata->lock_visor_dev);
 }
 
 static int
@@ -627,16 +669,24 @@ visorinput_pause(struct visor_device *dev,
 		goto out;
 	}
 
-	down_write(&devdata->lock_visor_dev);
+	mutex_lock(&devdata->lock_visor_dev);
 	if (devdata->paused) {
 		rc = -EBUSY;
 		goto out_locked;
 	}
+	if (devdata->interrupts_enabled)
+		visorbus_disable_channel_interrupts(dev);
+
+	/*
+	 * due to above, at this time no thread of execution will be
+	 * in visorinput_channel_interrupt()
+	 */
+
 	devdata->paused = true;
 	complete_func(dev, 0);
 	rc = 0;
 out_locked:
-	up_write(&devdata->lock_visor_dev);
+	mutex_unlock(&devdata->lock_visor_dev);
 out:
 	return rc;
 }
@@ -652,16 +702,25 @@ visorinput_resume(struct visor_device *dev,
 		rc = -ENODEV;
 		goto out;
 	}
-	down_write(&devdata->lock_visor_dev);
+	mutex_lock(&devdata->lock_visor_dev);
 	if (!devdata->paused) {
 		rc = -EBUSY;
 		goto out_locked;
 	}
 	devdata->paused = false;
 	complete_func(dev, 0);
+
+	/*
+	 * Re-establish calls to visorinput_channel_interrupt() if that is
+	 * the desired state that we've kept track of in interrupts_enabled
+	 * while the device was paused.
+	 */
+	if (devdata->interrupts_enabled)
+		visorbus_enable_channel_interrupts(dev);
+
 	rc = 0;
 out_locked:
-	up_write(&devdata->lock_visor_dev);
+	mutex_unlock(&devdata->lock_visor_dev);
 out:
 	return rc;
 }
@@ -675,7 +734,6 @@ static struct visor_channeltype_descriptor visorinput_channel_types[] = {
 
 static struct visor_driver visorinput_driver = {
 	.name = "visorinput",
-	.vertag = NULL,
 	.owner = THIS_MODULE,
 	.channel_types = visorinput_channel_types,
 	.probe = visorinput_probe,
@@ -704,8 +762,7 @@ MODULE_DEVICE_TABLE(visorbus, visorinput_channel_types);
 
 MODULE_AUTHOR("Unisys");
 MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("s-Par human input driver for guest Linux");
-MODULE_VERSION(VERSION);
+MODULE_DESCRIPTION("s-Par human input driver for virtual keyboard/mouse");
 
 MODULE_ALIAS("visorbus:" SPAR_MOUSE_CHANNEL_PROTOCOL_UUID_STR);
 MODULE_ALIAS("visorbus:" SPAR_KEYBOARD_CHANNEL_PROTOCOL_UUID_STR);