---

yaml
---
r: 113668
b: refs/heads/master
c: 8d71ff0
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 92562927826fceb2f8e69c89e28161b8c1e0b125
+refs/heads/master: 8d71ff0bef9cf4e70108a9a2762f2361e607abde

trunk/Documentation/00-INDEX

@@ -159,8 +159,6 @@ hayes-esp.txt
 	- info on using the Hayes ESP serial driver.
 highuid.txt
 	- notes on the change from 16 bit to 32 bit user/group IDs.
-hpet.txt
-	- High Precision Event Timer Driver for Linux.
 timers/
 	- info on the timer related topics
 hw_random.txt

trunk/Documentation/feature-removal-schedule.txt

@@ -287,14 +287,6 @@ Who:	Glauber Costa <gcosta@redhat.com>
 
 ---------------------------
 
-What:	old style serial driver for ColdFire (CONFIG_SERIAL_COLDFIRE)
-When:	2.6.28
-Why:	This driver still uses the old interface and has been replaced
-	by CONFIG_SERIAL_MCF.
-Who:	Sebastian Siewior <sebastian@breakpoint.cc>
-
----------------------------
-
 What:	/sys/o2cb symlink
 When:	January 2010
 Why:	/sys/fs/o2cb is the proper location for this information - /sys/o2cb

trunk/Documentation/filesystems/ext4.txt

@@ -223,6 +223,11 @@ errors=remount-ro(*)	Remount the filesystem read-only on an error.
 errors=continue		Keep going on a filesystem error.
 errors=panic		Panic and halt the machine if an error occurs.
 
+data_err=ignore(*)	Just print an error message if an error occurs
+			in a file data buffer in ordered mode.
+data_err=abort		Abort the journal if an error occurs in a file
+			data buffer in ordered mode.
+
 grpid			Give objects the same group ID as their creator.
 bsdgroups
 

trunk/Documentation/timers/00-INDEX

@@ -0,0 +1,10 @@
+00-INDEX
+	- this file
+highres.txt
+	- High resolution timers and dynamic ticks design notes
+hpet.txt
+	- High Precision Event Timer Driver for Linux
+hrtimers.txt
+	- subsystem for high-resolution kernel timers
+timer_stats.txt
+	- timer usage statistics

trunk/Documentation/hpet.txt → trunk/Documentation/timers/hpet.txt

@@ -1,21 +1,32 @@
 		High Precision Event Timer Driver for Linux
 
-The High Precision Event Timer (HPET) hardware is the future replacement
-for the 8254 and Real Time Clock (RTC) periodic timer functionality.
-Each HPET can have up to 32 timers.  It is possible to configure the
-first two timers as legacy replacements for 8254 and RTC periodic timers.
-A specification done by Intel and Microsoft can be found at
-<http://www.intel.com/technology/architecture/hpetspec.htm>.
+The High Precision Event Timer (HPET) hardware follows a specification
+by Intel and Microsoft which can be found at
+
+	http://www.intel.com/technology/architecture/hpetspec.htm
+
+Each HPET has one fixed-rate counter (at 10+ MHz, hence "High Precision")
+and up to 32 comparators.  Normally three or more comparators are provided,
+each of which can generate oneshot interupts and at least one of which has
+additional hardware to support periodic interrupts.  The comparators are
+also called "timers", which can be misleading since usually timers are
+independent of each other ... these share a counter, complicating resets.
+
+HPET devices can support two interrupt routing modes.  In one mode, the
+comparators are additional interrupt sources with no particular system
+role.  Many x86 BIOS writers don't route HPET interrupts at all, which
+prevents use of that mode.  They support the other "legacy replacement"
+mode where the first two comparators block interrupts from 8254 timers
+and from the RTC.
 
 The driver supports detection of HPET driver allocation and initialization
 of the HPET before the driver module_init routine is called.  This enables
 platform code which uses timer 0 or 1 as the main timer to intercept HPET
 initialization.  An example of this initialization can be found in
-arch/i386/kernel/time_hpet.c.
+arch/x86/kernel/hpet.c.
 
-The driver provides two APIs which are very similar to the API found in
-the rtc.c driver.  There is a user space API and a kernel space API.
-An example user space program is provided below.
+The driver provides a userspace API which resembles the API found in the
+RTC driver framework.  An example user space program is provided below.
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -286,15 +297,3 @@ out:
 
 	return;
 }
-
-The kernel API has three interfaces exported from the driver:
-
-	hpet_register(struct hpet_task *tp, int periodic)
-	hpet_unregister(struct hpet_task *tp)
-	hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg)
-
-The kernel module using this interface fills in the ht_func and ht_data
-members of the hpet_task structure before calling hpet_register.
-hpet_control simply vectors to the hpet_ioctl routine and has the same
-commands and respective arguments as the user API.  hpet_unregister
-is used to terminate usage of the HPET timer reserved by hpet_register.