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-rw-r--r--Documentation/DocBook/Makefile2
-rw-r--r--Documentation/DocBook/uio-howto.tmpl90
-rw-r--r--drivers/base/core.c4
-rw-r--r--drivers/base/power/Makefile3
-rw-r--r--drivers/base/power/main.c8
-rw-r--r--drivers/base/power/power.h28
-rw-r--r--drivers/char/Kconfig2
-rw-r--r--fs/sysfs/file.c6
-rw-r--r--lib/kobject.c4
9 files changed, 68 insertions, 79 deletions
diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile
index 054a7ecf64c..4953bc25872 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 c119484258b..fdd7f4f887b 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 3f4d6aa1399..2683eac30c6 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 a803733c839..44504e6618f 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 0ab4ab21f56..691ffb64cc3 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 5c4efd493fa..379da4e958e 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 bf18d757b87..a509b8d7978 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 27d1785b764..4045bdcc4b3 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 a7e3bf4d3c7..b52e9f4ef37 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;