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authorDavid S. Miller <davem@davemloft.net>2010-04-11 05:44:30 -0400
committerDavid S. Miller <davem@davemloft.net>2010-04-11 05:44:30 -0400
commit4a1032faac94ebbf647460ae3e06fc21146eb280 (patch)
tree7f31b97beb0406faa1523e619289ad0ab07c9787 /Documentation
parentae4e8d63b5619d4d95f1d2bfa2b836caa6e62d06 (diff)
parent0eddb519b9127c73d53db4bf3ec1d45b13f844d1 (diff)
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/DMA-API-HOWTO.txt (renamed from Documentation/PCI/PCI-DMA-mapping.txt)0
-rw-r--r--Documentation/DocBook/tracepoint.tmpl13
-rw-r--r--Documentation/block/biodoc.txt4
-rw-r--r--Documentation/cgroups/memory.txt2
-rw-r--r--Documentation/circular-buffers.txt234
-rw-r--r--Documentation/connector/cn_test.c1
-rw-r--r--Documentation/fb/efifb.txt (renamed from Documentation/fb/imacfb.txt)14
-rw-r--r--Documentation/filesystems/00-INDEX2
-rw-r--r--Documentation/filesystems/9p.txt18
-rw-r--r--Documentation/filesystems/ceph.txt11
-rw-r--r--Documentation/filesystems/tmpfs.txt6
-rw-r--r--Documentation/memory-barriers.txt20
-rw-r--r--Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt54
-rw-r--r--Documentation/sound/alsa/HD-Audio.txt16
-rw-r--r--Documentation/volatile-considered-harmful.txt6
-rw-r--r--Documentation/watchdog/src/watchdog-simple.c3
-rw-r--r--Documentation/watchdog/src/watchdog-test.c8
-rw-r--r--Documentation/watchdog/watchdog-api.txt5
18 files changed, 384 insertions, 33 deletions
diff --git a/Documentation/PCI/PCI-DMA-mapping.txt b/Documentation/DMA-API-HOWTO.txt
index 52618ab069ad..52618ab069ad 100644
--- a/Documentation/PCI/PCI-DMA-mapping.txt
+++ b/Documentation/DMA-API-HOWTO.txt
diff --git a/Documentation/DocBook/tracepoint.tmpl b/Documentation/DocBook/tracepoint.tmpl
index 8bca1d5cec09..e8473eae2a20 100644
--- a/Documentation/DocBook/tracepoint.tmpl
+++ b/Documentation/DocBook/tracepoint.tmpl
@@ -16,6 +16,15 @@
16 </address> 16 </address>
17 </affiliation> 17 </affiliation>
18 </author> 18 </author>
19 <author>
20 <firstname>William</firstname>
21 <surname>Cohen</surname>
22 <affiliation>
23 <address>
24 <email>wcohen@redhat.com</email>
25 </address>
26 </affiliation>
27 </author>
19 </authorgroup> 28 </authorgroup>
20 29
21 <legalnotice> 30 <legalnotice>
@@ -91,4 +100,8 @@
91!Iinclude/trace/events/signal.h 100!Iinclude/trace/events/signal.h
92 </chapter> 101 </chapter>
93 102
103 <chapter id="block">
104 <title>Block IO</title>
105!Iinclude/trace/events/block.h
106 </chapter>
94</book> 107</book>
diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt
index 6fab97ea7e6b..508b5b2b0289 100644
--- a/Documentation/block/biodoc.txt
+++ b/Documentation/block/biodoc.txt
@@ -1162,8 +1162,8 @@ where a driver received a request ala this before:
1162 1162
1163As mentioned, there is no virtual mapping of a bio. For DMA, this is 1163As mentioned, there is no virtual mapping of a bio. For DMA, this is
1164not a problem as the driver probably never will need a virtual mapping. 1164not a problem as the driver probably never will need a virtual mapping.
1165Instead it needs a bus mapping (pci_map_page for a single segment or 1165Instead it needs a bus mapping (dma_map_page for a single segment or
1166use blk_rq_map_sg for scatter gather) to be able to ship it to the driver. For 1166use dma_map_sg for scatter gather) to be able to ship it to the driver. For
1167PIO drivers (or drivers that need to revert to PIO transfer once in a 1167PIO drivers (or drivers that need to revert to PIO transfer once in a
1168while (IDE for example)), where the CPU is doing the actual data 1168while (IDE for example)), where the CPU is doing the actual data
1169transfer a virtual mapping is needed. If the driver supports highmem I/O, 1169transfer a virtual mapping is needed. If the driver supports highmem I/O,
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
index f8bc802d70b9..3a6aecd078ba 100644
--- a/Documentation/cgroups/memory.txt
+++ b/Documentation/cgroups/memory.txt
@@ -340,7 +340,7 @@ Note:
3405.3 swappiness 3405.3 swappiness
341 Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of groups only. 341 Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of groups only.
342 342
343 Following cgroups' swapiness can't be changed. 343 Following cgroups' swappiness can't be changed.
344 - root cgroup (uses /proc/sys/vm/swappiness). 344 - root cgroup (uses /proc/sys/vm/swappiness).
345 - a cgroup which uses hierarchy and it has child cgroup. 345 - a cgroup which uses hierarchy and it has child cgroup.
346 - a cgroup which uses hierarchy and not the root of hierarchy. 346 - a cgroup which uses hierarchy and not the root of hierarchy.
diff --git a/Documentation/circular-buffers.txt b/Documentation/circular-buffers.txt
new file mode 100644
index 000000000000..8117e5bf6065
--- /dev/null
+++ b/Documentation/circular-buffers.txt
@@ -0,0 +1,234 @@
1 ================
2 CIRCULAR BUFFERS
3 ================
4
5By: David Howells <dhowells@redhat.com>
6 Paul E. McKenney <paulmck@linux.vnet.ibm.com>
7
8
9Linux provides a number of features that can be used to implement circular
10buffering. There are two sets of such features:
11
12 (1) Convenience functions for determining information about power-of-2 sized
13 buffers.
14
15 (2) Memory barriers for when the producer and the consumer of objects in the
16 buffer don't want to share a lock.
17
18To use these facilities, as discussed below, there needs to be just one
19producer and just one consumer. It is possible to handle multiple producers by
20serialising them, and to handle multiple consumers by serialising them.
21
22
23Contents:
24
25 (*) What is a circular buffer?
26
27 (*) Measuring power-of-2 buffers.
28
29 (*) Using memory barriers with circular buffers.
30 - The producer.
31 - The consumer.
32
33
34==========================
35WHAT IS A CIRCULAR BUFFER?
36==========================
37
38First of all, what is a circular buffer? A circular buffer is a buffer of
39fixed, finite size into which there are two indices:
40
41 (1) A 'head' index - the point at which the producer inserts items into the
42 buffer.
43
44 (2) A 'tail' index - the point at which the consumer finds the next item in
45 the buffer.
46
47Typically when the tail pointer is equal to the head pointer, the buffer is
48empty; and the buffer is full when the head pointer is one less than the tail
49pointer.
50
51The head index is incremented when items are added, and the tail index when
52items are removed. The tail index should never jump the head index, and both
53indices should be wrapped to 0 when they reach the end of the buffer, thus
54allowing an infinite amount of data to flow through the buffer.
55
56Typically, items will all be of the same unit size, but this isn't strictly
57required to use the techniques below. The indices can be increased by more
58than 1 if multiple items or variable-sized items are to be included in the
59buffer, provided that neither index overtakes the other. The implementer must
60be careful, however, as a region more than one unit in size may wrap the end of
61the buffer and be broken into two segments.
62
63
64============================
65MEASURING POWER-OF-2 BUFFERS
66============================
67
68Calculation of the occupancy or the remaining capacity of an arbitrarily sized
69circular buffer would normally be a slow operation, requiring the use of a
70modulus (divide) instruction. However, if the buffer is of a power-of-2 size,
71then a much quicker bitwise-AND instruction can be used instead.
72
73Linux provides a set of macros for handling power-of-2 circular buffers. These
74can be made use of by:
75
76 #include <linux/circ_buf.h>
77
78The macros are:
79
80 (*) Measure the remaining capacity of a buffer:
81
82 CIRC_SPACE(head_index, tail_index, buffer_size);
83
84 This returns the amount of space left in the buffer[1] into which items
85 can be inserted.
86
87
88 (*) Measure the maximum consecutive immediate space in a buffer:
89
90 CIRC_SPACE_TO_END(head_index, tail_index, buffer_size);
91
92 This returns the amount of consecutive space left in the buffer[1] into
93 which items can be immediately inserted without having to wrap back to the
94 beginning of the buffer.
95
96
97 (*) Measure the occupancy of a buffer:
98
99 CIRC_CNT(head_index, tail_index, buffer_size);
100
101 This returns the number of items currently occupying a buffer[2].
102
103
104 (*) Measure the non-wrapping occupancy of a buffer:
105
106 CIRC_CNT_TO_END(head_index, tail_index, buffer_size);
107
108 This returns the number of consecutive items[2] that can be extracted from
109 the buffer without having to wrap back to the beginning of the buffer.
110
111
112Each of these macros will nominally return a value between 0 and buffer_size-1,
113however:
114
115 [1] CIRC_SPACE*() are intended to be used in the producer. To the producer
116 they will return a lower bound as the producer controls the head index,
117 but the consumer may still be depleting the buffer on another CPU and
118 moving the tail index.
119
120 To the consumer it will show an upper bound as the producer may be busy
121 depleting the space.
122
123 [2] CIRC_CNT*() are intended to be used in the consumer. To the consumer they
124 will return a lower bound as the consumer controls the tail index, but the
125 producer may still be filling the buffer on another CPU and moving the
126 head index.
127
128 To the producer it will show an upper bound as the consumer may be busy
129 emptying the buffer.
130
131 [3] To a third party, the order in which the writes to the indices by the
132 producer and consumer become visible cannot be guaranteed as they are
133 independent and may be made on different CPUs - so the result in such a
134 situation will merely be a guess, and may even be negative.
135
136
137===========================================
138USING MEMORY BARRIERS WITH CIRCULAR BUFFERS
139===========================================
140
141By using memory barriers in conjunction with circular buffers, you can avoid
142the need to:
143
144 (1) use a single lock to govern access to both ends of the buffer, thus
145 allowing the buffer to be filled and emptied at the same time; and
146
147 (2) use atomic counter operations.
148
149There are two sides to this: the producer that fills the buffer, and the
150consumer that empties it. Only one thing should be filling a buffer at any one
151time, and only one thing should be emptying a buffer at any one time, but the
152two sides can operate simultaneously.
153
154
155THE PRODUCER
156------------
157
158The producer will look something like this:
159
160 spin_lock(&producer_lock);
161
162 unsigned long head = buffer->head;
163 unsigned long tail = ACCESS_ONCE(buffer->tail);
164
165 if (CIRC_SPACE(head, tail, buffer->size) >= 1) {
166 /* insert one item into the buffer */
167 struct item *item = buffer[head];
168
169 produce_item(item);
170
171 smp_wmb(); /* commit the item before incrementing the head */
172
173 buffer->head = (head + 1) & (buffer->size - 1);
174
175 /* wake_up() will make sure that the head is committed before
176 * waking anyone up */
177 wake_up(consumer);
178 }
179
180 spin_unlock(&producer_lock);
181
182This will instruct the CPU that the contents of the new item must be written
183before the head index makes it available to the consumer and then instructs the
184CPU that the revised head index must be written before the consumer is woken.
185
186Note that wake_up() doesn't have to be the exact mechanism used, but whatever
187is used must guarantee a (write) memory barrier between the update of the head
188index and the change of state of the consumer, if a change of state occurs.
189
190
191THE CONSUMER
192------------
193
194The consumer will look something like this:
195
196 spin_lock(&consumer_lock);
197
198 unsigned long head = ACCESS_ONCE(buffer->head);
199 unsigned long tail = buffer->tail;
200
201 if (CIRC_CNT(head, tail, buffer->size) >= 1) {
202 /* read index before reading contents at that index */
203 smp_read_barrier_depends();
204
205 /* extract one item from the buffer */
206 struct item *item = buffer[tail];
207
208 consume_item(item);
209
210 smp_mb(); /* finish reading descriptor before incrementing tail */
211
212 buffer->tail = (tail + 1) & (buffer->size - 1);
213 }
214
215 spin_unlock(&consumer_lock);
216
217This will instruct the CPU to make sure the index is up to date before reading
218the new item, and then it shall make sure the CPU has finished reading the item
219before it writes the new tail pointer, which will erase the item.
220
221
222Note the use of ACCESS_ONCE() in both algorithms to read the opposition index.
223This prevents the compiler from discarding and reloading its cached value -
224which some compilers will do across smp_read_barrier_depends(). This isn't
225strictly needed if you can be sure that the opposition index will _only_ be
226used the once.
227
228
229===============
230FURTHER READING
231===============
232
233See also Documentation/memory-barriers.txt for a description of Linux's memory
234barrier facilities.
diff --git a/Documentation/connector/cn_test.c b/Documentation/connector/cn_test.c
index b07add3467f1..7764594778d4 100644
--- a/Documentation/connector/cn_test.c
+++ b/Documentation/connector/cn_test.c
@@ -25,6 +25,7 @@
25#include <linux/module.h> 25#include <linux/module.h>
26#include <linux/moduleparam.h> 26#include <linux/moduleparam.h>
27#include <linux/skbuff.h> 27#include <linux/skbuff.h>
28#include <linux/slab.h>
28#include <linux/timer.h> 29#include <linux/timer.h>
29 30
30#include <linux/connector.h> 31#include <linux/connector.h>
diff --git a/Documentation/fb/imacfb.txt b/Documentation/fb/efifb.txt
index 316ec9bb7deb..a59916c29b33 100644
--- a/Documentation/fb/imacfb.txt
+++ b/Documentation/fb/efifb.txt
@@ -1,9 +1,9 @@
1 1
2What is imacfb? 2What is efifb?
3=============== 3===============
4 4
5This is a generic EFI platform driver for Intel based Apple computers. 5This is a generic EFI platform driver for Intel based Apple computers.
6Imacfb is only for EFI booted Intel Macs. 6efifb is only for EFI booted Intel Macs.
7 7
8Supported Hardware 8Supported Hardware
9================== 9==================
@@ -16,16 +16,16 @@ MacMini
16How to use it? 16How to use it?
17============== 17==============
18 18
19Imacfb does not have any kind of autodetection of your machine. 19efifb does not have any kind of autodetection of your machine.
20You have to add the following kernel parameters in your elilo.conf: 20You have to add the following kernel parameters in your elilo.conf:
21 Macbook : 21 Macbook :
22 video=imacfb:macbook 22 video=efifb:macbook
23 MacMini : 23 MacMini :
24 video=imacfb:mini 24 video=efifb:mini
25 Macbook Pro 15", iMac 17" : 25 Macbook Pro 15", iMac 17" :
26 video=imacfb:i17 26 video=efifb:i17
27 Macbook Pro 17", iMac 20" : 27 Macbook Pro 17", iMac 20" :
28 video=imacfb:i20 28 video=efifb:i20
29 29
30-- 30--
31Edgar Hucek <gimli@dark-green.com> 31Edgar Hucek <gimli@dark-green.com>
diff --git a/Documentation/filesystems/00-INDEX b/Documentation/filesystems/00-INDEX
index 3bae418c6ad3..4303614b5add 100644
--- a/Documentation/filesystems/00-INDEX
+++ b/Documentation/filesystems/00-INDEX
@@ -16,6 +16,8 @@ befs.txt
16 - information about the BeOS filesystem for Linux. 16 - information about the BeOS filesystem for Linux.
17bfs.txt 17bfs.txt
18 - info for the SCO UnixWare Boot Filesystem (BFS). 18 - info for the SCO UnixWare Boot Filesystem (BFS).
19ceph.txt
20 - info for the Ceph Distributed File System
19cifs.txt 21cifs.txt
20 - description of the CIFS filesystem. 22 - description of the CIFS filesystem.
21coda.txt 23coda.txt
diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt
index 57e0b80a5274..c0236e753bc8 100644
--- a/Documentation/filesystems/9p.txt
+++ b/Documentation/filesystems/9p.txt
@@ -37,6 +37,15 @@ For Plan 9 From User Space applications (http://swtch.com/plan9)
37 37
38 mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER 38 mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER
39 39
40For server running on QEMU host with virtio transport:
41
42 mount -t 9p -o trans=virtio <mount_tag> /mnt/9
43
44where mount_tag is the tag associated by the server to each of the exported
45mount points. Each 9P export is seen by the client as a virtio device with an
46associated "mount_tag" property. Available mount tags can be
47seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files.
48
40OPTIONS 49OPTIONS
41======= 50=======
42 51
@@ -47,7 +56,7 @@ OPTIONS
47 fd - used passed file descriptors for connection 56 fd - used passed file descriptors for connection
48 (see rfdno and wfdno) 57 (see rfdno and wfdno)
49 virtio - connect to the next virtio channel available 58 virtio - connect to the next virtio channel available
50 (from lguest or KVM with trans_virtio module) 59 (from QEMU with trans_virtio module)
51 rdma - connect to a specified RDMA channel 60 rdma - connect to a specified RDMA channel
52 61
53 uname=name user name to attempt mount as on the remote server. The 62 uname=name user name to attempt mount as on the remote server. The
@@ -85,7 +94,12 @@ OPTIONS
85 94
86 port=n port to connect to on the remote server 95 port=n port to connect to on the remote server
87 96
88 noextend force legacy mode (no 9p2000.u semantics) 97 noextend force legacy mode (no 9p2000.u or 9p2000.L semantics)
98
99 version=name Select 9P protocol version. Valid options are:
100 9p2000 - Legacy mode (same as noextend)
101 9p2000.u - Use 9P2000.u protocol
102 9p2000.L - Use 9P2000.L protocol
89 103
90 dfltuid attempt to mount as a particular uid 104 dfltuid attempt to mount as a particular uid
91 105
diff --git a/Documentation/filesystems/ceph.txt b/Documentation/filesystems/ceph.txt
index 6e03917316bd..0660c9f5deef 100644
--- a/Documentation/filesystems/ceph.txt
+++ b/Documentation/filesystems/ceph.txt
@@ -8,7 +8,7 @@ Basic features include:
8 8
9 * POSIX semantics 9 * POSIX semantics
10 * Seamless scaling from 1 to many thousands of nodes 10 * Seamless scaling from 1 to many thousands of nodes
11 * High availability and reliability. No single points of failure. 11 * High availability and reliability. No single point of failure.
12 * N-way replication of data across storage nodes 12 * N-way replication of data across storage nodes
13 * Fast recovery from node failures 13 * Fast recovery from node failures
14 * Automatic rebalancing of data on node addition/removal 14 * Automatic rebalancing of data on node addition/removal
@@ -94,7 +94,7 @@ Mount Options
94 94
95 wsize=X 95 wsize=X
96 Specify the maximum write size in bytes. By default there is no 96 Specify the maximum write size in bytes. By default there is no
97 maximu. Ceph will normally size writes based on the file stripe 97 maximum. Ceph will normally size writes based on the file stripe
98 size. 98 size.
99 99
100 rsize=X 100 rsize=X
@@ -115,7 +115,7 @@ Mount Options
115 number of entries in that directory. 115 number of entries in that directory.
116 116
117 nocrc 117 nocrc
118 Disable CRC32C calculation for data writes. If set, the OSD 118 Disable CRC32C calculation for data writes. If set, the storage node
119 must rely on TCP's error correction to detect data corruption 119 must rely on TCP's error correction to detect data corruption
120 in the data payload. 120 in the data payload.
121 121
@@ -133,7 +133,8 @@ For more information on Ceph, see the home page at
133 http://ceph.newdream.net/ 133 http://ceph.newdream.net/
134 134
135The Linux kernel client source tree is available at 135The Linux kernel client source tree is available at
136 git://ceph.newdream.net/linux-ceph-client.git 136 git://ceph.newdream.net/git/ceph-client.git
137 git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client.git
137 138
138and the source for the full system is at 139and the source for the full system is at
139 git://ceph.newdream.net/ceph.git 140 git://ceph.newdream.net/git/ceph.git
diff --git a/Documentation/filesystems/tmpfs.txt b/Documentation/filesystems/tmpfs.txt
index 3015da0c6b2a..fe09a2cb1858 100644
--- a/Documentation/filesystems/tmpfs.txt
+++ b/Documentation/filesystems/tmpfs.txt
@@ -82,11 +82,13 @@ tmpfs has a mount option to set the NUMA memory allocation policy for
82all files in that instance (if CONFIG_NUMA is enabled) - which can be 82all files in that instance (if CONFIG_NUMA is enabled) - which can be
83adjusted on the fly via 'mount -o remount ...' 83adjusted on the fly via 'mount -o remount ...'
84 84
85mpol=default prefers to allocate memory from the local node 85mpol=default use the process allocation policy
86 (see set_mempolicy(2))
86mpol=prefer:Node prefers to allocate memory from the given Node 87mpol=prefer:Node prefers to allocate memory from the given Node
87mpol=bind:NodeList allocates memory only from nodes in NodeList 88mpol=bind:NodeList allocates memory only from nodes in NodeList
88mpol=interleave prefers to allocate from each node in turn 89mpol=interleave prefers to allocate from each node in turn
89mpol=interleave:NodeList allocates from each node of NodeList in turn 90mpol=interleave:NodeList allocates from each node of NodeList in turn
91mpol=local prefers to allocate memory from the local node
90 92
91NodeList format is a comma-separated list of decimal numbers and ranges, 93NodeList format is a comma-separated list of decimal numbers and ranges,
92a range being two hyphen-separated decimal numbers, the smallest and 94a range being two hyphen-separated decimal numbers, the smallest and
@@ -134,3 +136,5 @@ Author:
134 Christoph Rohland <cr@sap.com>, 1.12.01 136 Christoph Rohland <cr@sap.com>, 1.12.01
135Updated: 137Updated:
136 Hugh Dickins, 4 June 2007 138 Hugh Dickins, 4 June 2007
139Updated:
140 KOSAKI Motohiro, 16 Mar 2010
diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt
index 7f5809eddee6..631ad2f1b229 100644
--- a/Documentation/memory-barriers.txt
+++ b/Documentation/memory-barriers.txt
@@ -3,6 +3,7 @@
3 ============================ 3 ============================
4 4
5By: David Howells <dhowells@redhat.com> 5By: David Howells <dhowells@redhat.com>
6 Paul E. McKenney <paulmck@linux.vnet.ibm.com>
6 7
7Contents: 8Contents:
8 9
@@ -60,6 +61,10 @@ Contents:
60 61
61 - And then there's the Alpha. 62 - And then there's the Alpha.
62 63
64 (*) Example uses.
65
66 - Circular buffers.
67
63 (*) References. 68 (*) References.
64 69
65 70
@@ -2226,6 +2231,21 @@ The Alpha defines the Linux kernel's memory barrier model.
2226See the subsection on "Cache Coherency" above. 2231See the subsection on "Cache Coherency" above.
2227 2232
2228 2233
2234============
2235EXAMPLE USES
2236============
2237
2238CIRCULAR BUFFERS
2239----------------
2240
2241Memory barriers can be used to implement circular buffering without the need
2242of a lock to serialise the producer with the consumer. See:
2243
2244 Documentation/circular-buffers.txt
2245
2246for details.
2247
2248
2229========== 2249==========
2230REFERENCES 2250REFERENCES
2231========== 2251==========
diff --git a/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt b/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt
index 6e37be1eeb2d..4f8930263dd9 100644
--- a/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt
+++ b/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt
@@ -21,6 +21,15 @@ Required properties:
21- fsl,qe-num-snums: define how many serial number(SNUM) the QE can use for the 21- fsl,qe-num-snums: define how many serial number(SNUM) the QE can use for the
22 threads. 22 threads.
23 23
24Optional properties:
25- fsl,firmware-phandle:
26 Usage: required only if there is no fsl,qe-firmware child node
27 Value type: <phandle>
28 Definition: Points to a firmware node (see "QE Firmware Node" below)
29 that contains the firmware that should be uploaded for this QE.
30 The compatible property for the firmware node should say,
31 "fsl,qe-firmware".
32
24Recommended properties 33Recommended properties
25- brg-frequency : the internal clock source frequency for baud-rate 34- brg-frequency : the internal clock source frequency for baud-rate
26 generators in Hz. 35 generators in Hz.
@@ -59,3 +68,48 @@ Example:
59 reg = <0 c000>; 68 reg = <0 c000>;
60 }; 69 };
61 }; 70 };
71
72* QE Firmware Node
73
74This node defines a firmware binary that is embedded in the device tree, for
75the purpose of passing the firmware from bootloader to the kernel, or from
76the hypervisor to the guest.
77
78The firmware node itself contains the firmware binary contents, a compatible
79property, and any firmware-specific properties. The node should be placed
80inside a QE node that needs it. Doing so eliminates the need for a
81fsl,firmware-phandle property. Other QE nodes that need the same firmware
82should define an fsl,firmware-phandle property that points to the firmware node
83in the first QE node.
84
85The fsl,firmware property can be specified in the DTS (possibly using incbin)
86or can be inserted by the boot loader at boot time.
87
88Required properties:
89 - compatible
90 Usage: required
91 Value type: <string>
92 Definition: A standard property. Specify a string that indicates what
93 kind of firmware it is. For QE, this should be "fsl,qe-firmware".
94
95 - fsl,firmware
96 Usage: required
97 Value type: <prop-encoded-array>, encoded as an array of bytes
98 Definition: A standard property. This property contains the firmware
99 binary "blob".
100
101Example:
102 qe1@e0080000 {
103 compatible = "fsl,qe";
104 qe_firmware:qe-firmware {
105 compatible = "fsl,qe-firmware";
106 fsl,firmware = [0x70 0xcd 0x00 0x00 0x01 0x46 0x45 ...];
107 };
108 ...
109 };
110
111 qe2@e0090000 {
112 compatible = "fsl,qe";
113 fsl,firmware-phandle = <&qe_firmware>;
114 ...
115 };
diff --git a/Documentation/sound/alsa/HD-Audio.txt b/Documentation/sound/alsa/HD-Audio.txt
index f4dd3bf99d12..98d14cb8a85d 100644
--- a/Documentation/sound/alsa/HD-Audio.txt
+++ b/Documentation/sound/alsa/HD-Audio.txt
@@ -119,10 +119,18 @@ the codec slots 0 and 1 no matter what the hardware reports.
119 119
120Interrupt Handling 120Interrupt Handling
121~~~~~~~~~~~~~~~~~~ 121~~~~~~~~~~~~~~~~~~
122In rare but some cases, the interrupt isn't properly handled as 122HD-audio driver uses MSI as default (if available) since 2.6.33
123default. You would notice this by the DMA transfer error reported by 123kernel as MSI works better on some machines, and in general, it's
124ALSA PCM core, for example. Using MSI might help in such a case. 124better for performance. However, Nvidia controllers showed bad
125Pass `enable_msi=1` option for enabling MSI. 125regressions with MSI (especially in a combination with AMD chipset),
126thus we disabled MSI for them.
127
128There seem also still other devices that don't work with MSI. If you
129see a regression wrt the sound quality (stuttering, etc) or a lock-up
130in the recent kernel, try to pass `enable_msi=0` option to disable
131MSI. If it works, you can add the known bad device to the blacklist
132defined in hda_intel.c. In such a case, please report and give the
133patch back to the upstream developer.
126 134
127 135
128HD-AUDIO CODEC 136HD-AUDIO CODEC
diff --git a/Documentation/volatile-considered-harmful.txt b/Documentation/volatile-considered-harmful.txt
index 991c26a6ef64..db0cb228d64a 100644
--- a/Documentation/volatile-considered-harmful.txt
+++ b/Documentation/volatile-considered-harmful.txt
@@ -63,9 +63,9 @@ way to perform a busy wait is:
63 cpu_relax(); 63 cpu_relax();
64 64
65The cpu_relax() call can lower CPU power consumption or yield to a 65The cpu_relax() call can lower CPU power consumption or yield to a
66hyperthreaded twin processor; it also happens to serve as a memory barrier, 66hyperthreaded twin processor; it also happens to serve as a compiler
67so, once again, volatile is unnecessary. Of course, busy-waiting is 67barrier, so, once again, volatile is unnecessary. Of course, busy-
68generally an anti-social act to begin with. 68waiting is generally an anti-social act to begin with.
69 69
70There are still a few rare situations where volatile makes sense in the 70There are still a few rare situations where volatile makes sense in the
71kernel: 71kernel:
diff --git a/Documentation/watchdog/src/watchdog-simple.c b/Documentation/watchdog/src/watchdog-simple.c
index 4cf72f3fa8e9..ba45803a2216 100644
--- a/Documentation/watchdog/src/watchdog-simple.c
+++ b/Documentation/watchdog/src/watchdog-simple.c
@@ -17,9 +17,6 @@ int main(void)
17 ret = -1; 17 ret = -1;
18 break; 18 break;
19 } 19 }
20 ret = fsync(fd);
21 if (ret)
22 break;
23 sleep(10); 20 sleep(10);
24 } 21 }
25 close(fd); 22 close(fd);
diff --git a/Documentation/watchdog/src/watchdog-test.c b/Documentation/watchdog/src/watchdog-test.c
index a750532ffcf8..63fdc34ceb98 100644
--- a/Documentation/watchdog/src/watchdog-test.c
+++ b/Documentation/watchdog/src/watchdog-test.c
@@ -31,6 +31,8 @@ static void keep_alive(void)
31 */ 31 */
32int main(int argc, char *argv[]) 32int main(int argc, char *argv[])
33{ 33{
34 int flags;
35
34 fd = open("/dev/watchdog", O_WRONLY); 36 fd = open("/dev/watchdog", O_WRONLY);
35 37
36 if (fd == -1) { 38 if (fd == -1) {
@@ -41,12 +43,14 @@ int main(int argc, char *argv[])
41 43
42 if (argc > 1) { 44 if (argc > 1) {
43 if (!strncasecmp(argv[1], "-d", 2)) { 45 if (!strncasecmp(argv[1], "-d", 2)) {
44 ioctl(fd, WDIOC_SETOPTIONS, WDIOS_DISABLECARD); 46 flags = WDIOS_DISABLECARD;
47 ioctl(fd, WDIOC_SETOPTIONS, &flags);
45 fprintf(stderr, "Watchdog card disabled.\n"); 48 fprintf(stderr, "Watchdog card disabled.\n");
46 fflush(stderr); 49 fflush(stderr);
47 exit(0); 50 exit(0);
48 } else if (!strncasecmp(argv[1], "-e", 2)) { 51 } else if (!strncasecmp(argv[1], "-e", 2)) {
49 ioctl(fd, WDIOC_SETOPTIONS, WDIOS_ENABLECARD); 52 flags = WDIOS_ENABLECARD;
53 ioctl(fd, WDIOC_SETOPTIONS, &flags);
50 fprintf(stderr, "Watchdog card enabled.\n"); 54 fprintf(stderr, "Watchdog card enabled.\n");
51 fflush(stderr); 55 fflush(stderr);
52 exit(0); 56 exit(0);
diff --git a/Documentation/watchdog/watchdog-api.txt b/Documentation/watchdog/watchdog-api.txt
index 4cc4ba9d7150..eb7132ed8bbc 100644
--- a/Documentation/watchdog/watchdog-api.txt
+++ b/Documentation/watchdog/watchdog-api.txt
@@ -222,11 +222,10 @@ returned value is the temperature in degrees fahrenheit.
222 ioctl(fd, WDIOC_GETTEMP, &temperature); 222 ioctl(fd, WDIOC_GETTEMP, &temperature);
223 223
224Finally the SETOPTIONS ioctl can be used to control some aspects of 224Finally the SETOPTIONS ioctl can be used to control some aspects of
225the cards operation; right now the pcwd driver is the only one 225the cards operation.
226supporting this ioctl.
227 226
228 int options = 0; 227 int options = 0;
229 ioctl(fd, WDIOC_SETOPTIONS, options); 228 ioctl(fd, WDIOC_SETOPTIONS, &options);
230 229
231The following options are available: 230The following options are available:
232 231