9 files changed, 68 insertions, 79 deletions

diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile
index 054a7ecf64c6..4953bc258729 100644
--- a/Documentation/DocBook/Makefile
+++ b/Documentation/DocBook/Makefile
@@ -11,7 +11,7 @@ DOCBOOKS := wanbook.xml z8530book.xml mcabook.xml videobook.xml \
             procfs-guide.xml writing_usb_driver.xml \
             kernel-api.xml filesystems.xml lsm.xml usb.xml \
             gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \
-            genericirq.xml s390-drivers.xml
+            genericirq.xml s390-drivers.xml uio-howto.xml
 
 ###
 # The build process is as follows (targets):
diff --git a/Documentation/DocBook/uio-howto.tmpl b/Documentation/DocBook/uio-howto.tmpl
index c119484258b8..fdd7f4f887b7 100644
--- a/Documentation/DocBook/uio-howto.tmpl
+++ b/Documentation/DocBook/uio-howto.tmpl
@@ -30,6 +30,12 @@
 
 <revhistory>
         <revision>
+        <revnumber>0.4</revnumber>
+        <date>2007-11-26</date>
+        <authorinitials>hjk</authorinitials>
+        <revremark>Removed section about uio_dummy.</revremark>
+        </revision>
+        <revision>
         <revnumber>0.3</revnumber>
         <date>2007-04-29</date>
         <authorinitials>hjk</authorinitials>
@@ -94,6 +100,26 @@ interested in translating it, please email me
         user space. This simplifies development and reduces the risk of
         serious bugs within a kernel module.
         </para>
+        <para>
+        Please note that UIO is not an universal driver interface. Devices
+        that are already handled well by other kernel subsystems (like
+        networking or serial or USB) are no candidates for an UIO driver.
+        Hardware that is ideally suited for an UIO driver fulfills all of
+        the following:
+        </para>
+<itemizedlist>
+<listitem>
+        <para>The device has memory that can be mapped. The device can be
+        controlled completely by writing to this memory.</para>
+</listitem>
+<listitem>
+        <para>The device usually generates interrupts.</para>
+</listitem>
+<listitem>
+        <para>The device does not fit into one of the standard kernel
+        subsystems.</para>
+</listitem>
+</itemizedlist>
 </sect1>
 
 <sect1 id="thanks">
@@ -174,8 +200,9 @@ interested in translating it, please email me
         For cards that don't generate interrupts but need to be
         polled, there is the possibility to set up a timer that
         triggers the interrupt handler at configurable time intervals.
-        See <filename>drivers/uio/uio_dummy.c</filename> for an
-        example of this technique.
+        This interrupt simulation is done by calling
+        <function>uio_event_notify()</function>
+        from the timer's event handler.
         </para>
 
         <para>
@@ -263,63 +290,11 @@ offset = N * getpagesize();
 </sect1>
 </chapter>
 
-<chapter id="using-uio_dummy" xreflabel="Using uio_dummy">
-<?dbhtml filename="using-uio_dummy.html"?>
-<title>Using uio_dummy</title>
-        <para>
-        Well, there is no real use for uio_dummy. Its only purpose is
-        to test most parts of the UIO system (everything except
-        hardware interrupts), and to serve as an example for the
-        kernel module that you will have to write yourself.
-        </para>
-
-<sect1 id="what_uio_dummy_does">
-<title>What uio_dummy does</title>
-        <para>
-        The kernel module <filename>uio_dummy.ko</filename> creates a
-        device that uses a timer to generate periodic interrupts. The
-        interrupt handler does nothing but increment a counter. The
-        driver adds two custom attributes, <varname>count</varname>
-        and <varname>freq</varname>, that appear under
-        <filename>/sys/devices/platform/uio_dummy/</filename>.
-        </para>
-
-        <para>
-        The attribute <varname>count</varname> can be read and
-        written.  The associated file
-        <filename>/sys/devices/platform/uio_dummy/count</filename>
-        appears as a normal text file and contains the total number of
-        timer interrupts. If you look at it (e.g. using
-        <function>cat</function>), you'll notice it is slowly counting
-        up.
-        </para>
-
-        <para>
-        The attribute <varname>freq</varname> can be read and written.
-        The content of
-        <filename>/sys/devices/platform/uio_dummy/freq</filename>
-        represents the number of system timer ticks between two timer
-        interrupts. The default value of <varname>freq</varname> is
-        the value of the kernel variable <varname>HZ</varname>, which
-        gives you an interval of one second. Lower values will
-        increase the frequency. Try the following:
-        </para>
-<programlisting format="linespecific">
-cd /sys/devices/platform/uio_dummy/
-echo 100 > freq
-</programlisting>
-        <para>
-        Use <function>cat count</function> to see how the interrupt
-        frequency changes.
-        </para>
-</sect1>
-</chapter>
-
 <chapter id="custom_kernel_module" xreflabel="Writing your own kernel module">
 <?dbhtml filename="custom_kernel_module.html"?>
 <title>Writing your own kernel module</title>
         <para>
-        Please have a look at <filename>uio_dummy.c</filename> as an
+        Please have a look at <filename>uio_cif.c</filename> as an
         example. The following paragraphs explain the different
         sections of this file.
         </para>
@@ -354,9 +329,8 @@ See the description below for details.
 interrupt, it's your modules task to determine the irq number during
 initialization. If you don't have a hardware generated interrupt but
 want to trigger the interrupt handler in some other way, set
-<varname>irq</varname> to <varname>UIO_IRQ_CUSTOM</varname>. The
-uio_dummy module does this as it triggers the event mechanism in a timer
-routine. If you had no interrupt at all, you could set
+<varname>irq</varname> to <varname>UIO_IRQ_CUSTOM</varname>.
+If you had no interrupt at all, you could set
 <varname>irq</varname> to <varname>UIO_IRQ_NONE</varname>, though this
 rarely makes sense.
 </para></listitem>
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 3f4d6aa13990..2683eac30c68 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -770,9 +770,10 @@ int device_add(struct device *dev)
         error = device_add_attrs(dev);
         if (error)
                 goto AttrsError;
-        error = device_pm_add(dev);
+        error = dpm_sysfs_add(dev);
         if (error)
                 goto PMError;
+        device_pm_add(dev);
         error = bus_add_device(dev);
         if (error)
                 goto BusError;
@@ -797,6 +798,7 @@ int device_add(struct device *dev)
         return error;
  BusError:
         device_pm_remove(dev);
+        dpm_sysfs_remove(dev);
  PMError:
         if (dev->bus)
                 blocking_notifier_call_chain(&dev->bus->bus_notifier,
diff --git a/drivers/base/power/Makefile b/drivers/base/power/Makefile
index a803733c839e..44504e6618fb 100644
--- a/drivers/base/power/Makefile
+++ b/drivers/base/power/Makefile
@@ -1,5 +1,6 @@
 obj-y                   := shutdown.o
-obj-$(CONFIG_PM_SLEEP)  += main.o sysfs.o
+obj-$(CONFIG_PM)        += sysfs.o
+obj-$(CONFIG_PM_SLEEP)  += main.o
 obj-$(CONFIG_PM_TRACE)  += trace.o
 
 ifeq ($(CONFIG_DEBUG_DRIVER),y)
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 0ab4ab21f564..691ffb64cc37 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -38,20 +38,14 @@ static DEFINE_MUTEX(dpm_list_mtx);
 int (*platform_enable_wakeup)(struct device *dev, int is_on);
 
 
-int device_pm_add(struct device *dev)
+void device_pm_add(struct device *dev)
 {
-        int error;
-
         pr_debug("PM: Adding info for %s:%s\n",
                  dev->bus ? dev->bus->name : "No Bus",
                  kobject_name(&dev->kobj));
         mutex_lock(&dpm_list_mtx);
         list_add_tail(&dev->power.entry, &dpm_active);
-        error = dpm_sysfs_add(dev);
-        if (error)
-                list_del(&dev->power.entry);
         mutex_unlock(&dpm_list_mtx);
-        return error;
 }
 
 void device_pm_remove(struct device *dev)
diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h
index 5c4efd493fa5..379da4e958e0 100644
--- a/drivers/base/power/power.h
+++ b/drivers/base/power/power.h
@@ -13,14 +13,29 @@ extern void device_shutdown(void);
 
 extern struct list_head dpm_active;     /* The active device list */
 
-static inline struct device * to_device(struct list_head * entry)
+static inline struct device *to_device(struct list_head *entry)
 {
         return container_of(entry, struct device, power.entry);
 }
 
-extern int device_pm_add(struct device *);
+extern void device_pm_add(struct device *);
 extern void device_pm_remove(struct device *);
 
+#else /* CONFIG_PM_SLEEP */
+
+
+static inline void device_pm_add(struct device *dev)
+{
+}
+
+static inline void device_pm_remove(struct device *dev)
+{
+}
+
+#endif
+
+#ifdef CONFIG_PM
+
 /*
  * sysfs.c
  */
@@ -28,16 +43,15 @@ extern void device_pm_remove(struct device *);
 extern int dpm_sysfs_add(struct device *);
 extern void dpm_sysfs_remove(struct device *);
 
-#else /* CONFIG_PM_SLEEP */
-
+#else /* CONFIG_PM */
 
-static inline int device_pm_add(struct device * dev)
+static inline int dpm_sysfs_add(struct device *dev)
 {
         return 0;
 }
-static inline void device_pm_remove(struct device * dev)
-{
 
+static inline void dpm_sysfs_remove(struct device *dev)
+{
 }
 
 #endif
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index bf18d757b876..a509b8d79781 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -457,7 +457,7 @@ config LEGACY_PTYS
 config LEGACY_PTY_COUNT
         int "Maximum number of legacy PTY in use"
         depends on LEGACY_PTYS
-        range 1 256
+        range 0 256
         default "256"
         ---help---
           The maximum number of legacy PTYs that can be used at any one time.
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 27d1785b7644..4045bdcc4b33 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -119,7 +119,11 @@ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer
 
         sysfs_put_active_two(attr_sd);
 
-        BUG_ON(count > (ssize_t)PAGE_SIZE);
+        /*
+         * The code works fine with PAGE_SIZE return but it's likely to
+         * indicate truncated result or overflow in normal use cases.
+         */
+        BUG_ON(count >= (ssize_t)PAGE_SIZE);
         if (count >= 0) {
                 buffer->needs_read_fill = 0;
                 buffer->count = count;
diff --git a/lib/kobject.c b/lib/kobject.c
index a7e3bf4d3c70..b52e9f4ef371 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -313,8 +313,8 @@ int kobject_rename(struct kobject * kobj, const char *new_name)
                 struct kobject *temp_kobj;
                 temp_kobj = kset_find_obj(kobj->kset, new_name);
                 if (temp_kobj) {
-                        printk(KERN_WARNING "kobject '%s' can not be renamed "
-                               "to '%s' as '%s' is already in existance.\n",
+                        printk(KERN_WARNING "kobject '%s' cannot be renamed "
+                               "to '%s' as '%s' is already in existence.\n",
                                kobject_name(kobj), new_name, new_name);
                         kobject_put(temp_kobj);
                         return -EINVAL;