Commit b5c851a8 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

Merge branch 'linus' into tracing/core

Merge reason: merge latest tracing fixes to avoid conflicts in
              kernel/trace/trace_events_filter.c with upcoming change
Signed-off-by: default avatarIngo Molnar <>
parents eb02ce01 80a04d3f
......@@ -31,7 +31,7 @@ PS_METHOD = $(prefer-db2x)
# The targets that may be used.
PHONY += xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs
PHONY += xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs cleandocs
BOOKS := $(addprefix $(obj)/,$(DOCBOOKS))
xmldocs: $(BOOKS)
......@@ -213,11 +213,12 @@ silent_gen_xml = :
@echo ' Linux kernel internal documentation in different formats:'
@echo ' htmldocs - HTML'
@echo ' installmandocs - install man pages generated by mandocs'
@echo ' mandocs - man pages'
@echo ' pdfdocs - PDF'
@echo ' psdocs - Postscript'
@echo ' xmldocs - XML DocBook'
@echo ' mandocs - man pages'
@echo ' installmandocs - install man pages generated by mandocs'
@echo ' cleandocs - clean all generated DocBook files'
# Temporary files left by various tools
......@@ -235,6 +236,10 @@ clean-files := $(DOCBOOKS) \
clean-dirs := $(patsubst %.xml,%,$(DOCBOOKS)) man
$(Q)rm -f $(call objectify, $(clean-files))
$(Q)rm -rf $(call objectify, $(clean-dirs))
# Declare the contents of the .PHONY variable as phony. We keep that
# information in a variable se we can use it in if_changed and friends.
......@@ -428,3 +428,12 @@ Why: In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to
After a reasonable transition period, we will remove the legacy
fakephp interface.
Who: Alex Chiang <>
What: i2c-voodoo3 driver
When: October 2009
Why: Superseded by tdfxfb. I2C/DDC support used to live in a separate
driver but this caused driver conflicts.
Who: Jean Delvare <>
Krzysztof Helt <>
......@@ -24,6 +24,49 @@ Partitions and P_Keys
The P_Key for any interface is given by the "pkey" file, and the
main interface for a subinterface is in "parent."
Datagram vs Connected modes
The IPoIB driver supports two modes of operation: datagram and
connected. The mode is set and read through an interface's
/sys/class/net/<intf name>/mode file.
In datagram mode, the IB UD (Unreliable Datagram) transport is used
and so the interface MTU has is equal to the IB L2 MTU minus the
IPoIB encapsulation header (4 bytes). For example, in a typical IB
fabric with a 2K MTU, the IPoIB MTU will be 2048 - 4 = 2044 bytes.
In connected mode, the IB RC (Reliable Connected) transport is used.
Connected mode is to takes advantage of the connected nature of the
IB transport and allows an MTU up to the maximal IP packet size of
64K, which reduces the number of IP packets needed for handling
large UDP datagrams, TCP segments, etc and increases the performance
for large messages.
In connected mode, the interface's UD QP is still used for multicast
and communication with peers that don't support connected mode. In
this case, RX emulation of ICMP PMTU packets is used to cause the
networking stack to use the smaller UD MTU for these neighbours.
Stateless offloads
If the IB HW supports IPoIB stateless offloads, IPoIB advertises
TCP/IP checksum and/or Large Send (LSO) offloading capability to the
network stack.
Large Receive (LRO) offloading is also implemented and may be turned
on/off using ethtool calls. Currently LRO is supported only for
checksum offload capable devices.
Stateless offloads are supported only in datagram mode.
Interrupt moderation
If the underlying IB device supports CQ event moderation, one can
use ethtool to set interrupt mitigation parameters and thus reduce
the overhead incurred by handling interrupts. The main code path of
IPoIB doesn't use events for TX completion signaling so only RX
moderation is supported.
Debugging Information
By compiling the IPoIB driver with CONFIG_INFINIBAND_IPOIB_DEBUG set
......@@ -55,3 +98,5 @@ References
IP over InfiniBand (IPoIB) Architecture (RFC 4392)
IP over InfiniBand: Connected Mode (RFC 4755)
rotary-encoder - a generic driver for GPIO connected devices
Daniel Mack <>, Feb 2009
0. Function
Rotary encoders are devices which are connected to the CPU or other
peripherals with two wires. The outputs are phase-shifted by 90 degrees
and by triggering on falling and rising edges, the turn direction can
be determined.
The phase diagram of these two outputs look like this:
_____ _____ _____
| | | | | |
Channel A ____| |_____| |_____| |____
: : : : : : : : : : : :
__ _____ _____ _____
| | | | | | |
Channel B |_____| |_____| |_____| |__
: : : : : : : : : : : :
Event a b c d a b c d a b c d
one step
For more information, please see
1. Events / state machine
a) Rising edge on channel A, channel B in low state
This state is used to recognize a clockwise turn
b) Rising edge on channel B, channel A in high state
When entering this state, the encoder is put into 'armed' state,
meaning that there it has seen half the way of a one-step transition.
c) Falling edge on channel A, channel B in high state
This state is used to recognize a counter-clockwise turn
d) Falling edge on channel B, channel A in low state
Parking position. If the encoder enters this state, a full transition
should have happend, unless it flipped back on half the way. The
'armed' state tells us about that.
2. Platform requirements
As there is no hardware dependent call in this driver, the platform it is
used with must support gpiolib. Another requirement is that IRQs must be
able to fire on both edges.
3. Board integration
To use this driver in your system, register a platform_device with the
name 'rotary-encoder' and associate the IRQs and some specific platform
data with it.
struct rotary_encoder_platform_data is declared in
include/linux/rotary-encoder.h and needs to be filled with the number of
steps the encoder has and can carry information about externally inverted
signals (because of used invertig buffer or other reasons).
Because GPIO to IRQ mapping is platform specific, this information must
be given in seperately to the driver. See the example below.
/* board support file example */
#include <linux/input.h>
#include <linux/rotary_encoder.h>
#define GPIO_ROTARY_A 1
#define GPIO_ROTARY_B 2
static struct rotary_encoder_platform_data my_rotary_encoder_info = {
.steps = 24,
.axis = ABS_X,
.gpio_a = GPIO_ROTARY_A,
.gpio_b = GPIO_ROTARY_B,
.inverted_a = 0,
.inverted_b = 0,
static struct platform_device rotary_encoder_device = {
.name = "rotary-encoder",
.id = 0,
.dev = {
.platform_data = &my_rotary_encoder_info,
......@@ -40,10 +40,16 @@ This document describes the Linux kernel Makefiles.
--- 6.7 Custom kbuild commands
--- 6.8 Preprocessing linker scripts
=== 7 Kbuild Variables
=== 8 Makefile language
=== 9 Credits
=== 10 TODO
=== 7 Kbuild syntax for exported headers
--- 7.1 header-y
--- 7.2 objhdr-y
--- 7.3 destination-y
--- 7.4 unifdef-y (deprecated)
=== 8 Kbuild Variables
=== 9 Makefile language
=== 10 Credits
=== 11 TODO
=== 1 Overview
......@@ -1143,8 +1149,69 @@ When kbuild executes, the following steps are followed (roughly):
The kbuild infrastructure for *lds file are used in several
architecture-specific files.
=== 7 Kbuild syntax for exported headers
The kernel include a set of headers that is exported to userspace.
Many headers can be exported as-is but other headers requires a
minimal pre-processing before they are ready for user-space.
The pre-processing does:
- drop kernel specific annotations
- drop include of compiler.h
- drop all sections that is kernel internat (guarded by ifdef __KERNEL__)
Each relevant directory contain a file name "Kbuild" which specify the
headers to be exported.
See subsequent chapter for the syntax of the Kbuild file.
--- 7.1 header-y
header-y specify header files to be exported.
header-y += usb/
header-y += aio_abi.h
The convention is to list one file per line and
preferably in alphabetic order.
header-y also specify which subdirectories to visit.
A subdirectory is identified by a trailing '/' which
can be seen in the example above for the usb subdirectory.
Subdirectories are visited before their parent directories.
--- 7.2 objhdr-y
objhdr-y specifies generated files to be exported.
Generated files are special as they need to be looked
up in another directory when doing 'make O=...' builds.
objhdr-y += version.h
--- 7.3 destination-y
When an architecture have a set of exported headers that needs to be
exported to a different directory destination-y is used.
destination-y specify the destination directory for all exported
headers in the file where it is present.
destination-y := include/linux
In the example above all exported headers in the Kbuild file
will be located in the directory "include/linux" when exported.
--- 7.4 unifdef-y (deprecated)
unifdef-y is deprecated. A direct replacement is header-y.
=== 7 Kbuild Variables
=== 8 Kbuild Variables
The top Makefile exports the following variables:
......@@ -1206,7 +1273,7 @@ The top Makefile exports the following variables:
INSTALL_MOD_STRIP will used as the option(s) to the strip command.
=== 8 Makefile language
=== 9 Makefile language
The kernel Makefiles are designed to be run with GNU Make. The Makefiles
use only the documented features of GNU Make, but they do use many
......@@ -1225,14 +1292,14 @@ time the left-hand side is used.
There are some cases where "=" is appropriate. Usually, though, ":="
is the right choice.
=== 9 Credits
=== 10 Credits
Original version made by Michael Elizabeth Chastain, <>
Updates by Kai Germaschewski <>
Updates by Sam Ravnborg <>
Language QA by Jan Engelhardt <>
=== 10 TODO
=== 11 TODO
- Describe how kbuild supports shipped files with _shipped.
- Generating offset header files.
......@@ -42,6 +42,14 @@ sure that bitwise types don't get mixed up (little-endian vs big-endian
vs cpu-endian vs whatever), and there the constant "0" really _is_
__bitwise__ - to be used for relatively compact stuff (gfp_t, etc.) that
is mostly warning-free and is supposed to stay that way. Warnings will
be generated without __CHECK_ENDIAN__.
__bitwise - noisy stuff; in particular, __le*/__be* are that. We really
don't want to drown in noise unless we'd explicitly asked for it.
Getting sparse
This diff is collapsed.
......@@ -567,7 +567,7 @@ KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
# disable pointer signed / unsigned warnings in gcc 4.0
KBUILD_CFLAGS += $(call cc-option,-Wno-pointer-sign,)
# disable invalid "can't wrap" optimzations for signed / pointers
# disable invalid "can't wrap" optimizations for signed / pointers
KBUILD_CFLAGS += $(call cc-option,-fwrapv)
# revert to pre-gcc-4.4 behaviour of .eh_frame
......@@ -597,6 +597,10 @@ LDFLAGS_BUILD_ID = $(patsubst -Wl$(comma)%,%,\
LDFLAGS_vmlinux += -X
# Default kernel image to build when no specific target is given.
# KBUILD_IMAGE may be overruled on the command line or
# set in the environment
......@@ -1587,5 +1591,5 @@ PHONY += FORCE
# Declare the contents of the .PHONY variable as phony. We keep that
# information in a variable se we can use it in if_changed and friends.
# information in a variable so we can use it in if_changed and friends.
......@@ -109,3 +109,6 @@ config HAVE_CLK
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment