1. apt-get install linux-image-2.6.32-5-amd64-dbg 2. apt-get install kernel-patch-kdb
O S
kernel work log sound 0.11
$git fetch origin
$
$./scripts/checkpatch.pl --file --terse sound/sound_core.c | more
sound/sound_core.c:71: ERROR: trailing whitespace
sound/sound_core.c:83: ERROR: trailing whitespace
sound/sound_core.c:85: ERROR: trailing whitespace
sound/sound_core.c:115: ERROR: open brace '{' following
struct go on the same line
sound/sound_core.c:123: WARNING: externs should be avoided in .c files
sound/sound_core.c:126: WARNING: externs should be avoided in .c files
sound/sound_core.c:155: ERROR: do not initialise statics to 0 or NULL
sound/sound_core.c:163: ERROR: that open brace { should be on the
previous line
sound/sound_core.c:175: WARNING: line over 80 characters
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sound/sound_core.c:586: ERROR: trailing whitespace
sound/sound_core.c:633: ERROR: space required after that ',' (ctx:VxV)
total: 77 errors, 26 warnings, 667 lines checked
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. <fixing>
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total: 73 errors, 26 warnings, 666 lines checked
As an alternative to automatic variables, it is possible to define variables that are external to all functions, that is, variables that can be accessed by name by any function. (This mechanism is rather like Fortran COMMON or Pascal variables declared in the outermost block.) Because external variables are globally accessible, they can be used instead of argument lists to communicate data between functions. Furthermore, because external variables remain in existence permanently, rather than appearing and disappearing as functions are called and exited, they retain their values even after the functions that set them have returned.
. . . < fixing > . total: 28 errors, 23 warnings, 663 lines checked $./scripts/checkpatch.pl --file --terse sound/sound_core.c sound/sound_core.c:122: WARNING: externs should be avoided in .c files sound/sound_core.c:125: WARNING: externs should be avoided in .c files . . . . . total: 0 errors, 11 warnings, 662 lines checked $
write linux kernel patch 0.23 raw
write linux kernel patch 0.21 raw Contentgit clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git Initialized empty Git repository in /home/jeffrin/linux-2.6/.git/ remote: Counting objects: 1806930, done. remote: Compressing objects: 100% (278260/278260), done. Receiving objects: 14% (255365/1806930), 117.83 MiB | 127 KiB/s Resolving deltas: 100% (1513210/1513210), done.$cd linux-2.6 $./scripts/ge genksyms/ get_maintainer.pl $./scripts/get_maintainer.pl --file sound/ac97_bus.c Jaroslav Kysela <perex@perex.cz> Takashi Iwai <tiwai@suse.de> alsa-devel@alsa-project.org linux-kernel@vger.kernel.org $$ git status # On branch master nothing to commit (working directory clean) $ git branch jeffrin $ git branch jeffrin * master $ git checkout jeffrin Switched to branch 'jeffrin' $ $git status # On branch jeffrin nothing to commit (working directory clean) $ $./scripts/checkpatch.pl checkpatch.pl: no input files $./scripts/checkpatch.pl --file --terse sound/ac97_bus.c sound/ac97_bus.c:22: WARNING: line over 80 characters sound/ac97_bus.c:75: WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable total: 0 errors, 2 warnings, 77 lines checked$vim sound/ac97_bus.c +22 $./scripts/checkpatch.pl --file --terse sound/ac97_bus.c sound/ac97_bus.c:22: ERROR: trailing whitespace sound/ac97_bus.c:75: WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable total: 1 errors, 1 warnings, 77 lines checked $vim sound/ac97_bus.c +22 $./scripts/checkpatch.pl --file --terse sound/ac97_bus.c sound/ac97_bus.c:75: WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable total: 0 errors, 1 warnings, 77 lines checked $vim sound/ac97_bus.c +75$git status # On branch jeffrin # Changed but not updated: # (use "git add ..." to update what will be committed) # (use "git checkout -- ..." to discard changes in working directory) # # modified: sound/ac97_bus.c # no changes added to commit (use "git add" and/or "git commit -a") $git diff diff --git a/sound/ac97_bus.c b/sound/ac97_bus.c index a351dd0..c93251a 100644 --- a/sound/ac97_bus.c +++ b/sound/ac97_bus.c @@ -19,9 +19,9 @@ /* * Let drivers decide whether they want to support given codec from their - * probe method. Drivers have direct access to the struct snd_ac97 structure and may - * decide based on the id field amongst other things. - */ + * probe method. Drivers have direct access to the struct snd_ac97 + * structure and may decide based on the id field amongst other things. +*/ static int ac97_bus_match(struct device *dev, struct device_driver *drv) { return 1; $$git commit sound/ac97_bus.c [jeffrin a2c2867] sound: Fixed line limit issue in sound/ac97_bus.c This is a patch to the sound/ac97_bus.c file that fixes up a 80 character line limit issue found by the checkpatch.pl tool. Signed-off-by: Jeffrin Jose 1 files changed, 3 insertions(+), 3 deletions(-) $git show HEAD commit a2c2867876c246420a199a0fb4c36ad2965a42cc Author: Jeffrin Jose Date: Mon Dec 6 19:27:53 2010 +0530 sound: Fixed line limit issue in sound/ac97_bus.c This is a patch to the sound/ac97_bus.c file that fixes up a 80 character line limit issue found by the checkpatch.pl tool. Signed-off-by: Jeffrin Jose diff --git a/sound/ac97_bus.c b/sound/ac97_bus.c index a351dd0..c93251a 100644 --- a/sound/ac97_bus.c +++ b/sound/ac97_bus.c @@ -19,9 +19,9 @@ /* * Let drivers decide whether they want to support given codec from their - * probe method. Drivers have direct access to the struct snd_ac97 structure and may - * decide based on the id field amongst other things. - */ + * probe method. Drivers have direct access to the struct snd_ac97 + * structure and may decide based on the id field amongst other things. +*/ static int ac97_bus_match(struct device *dev, struct device_driver *drv) { return 1; $git format-patch master..jeffrin 0001-sound-Fixed-line-limit-issue-in-sound-ac97_bus.c.patch $./scripts/checkpatch.pl 0001-sound-Fixed-line-limit-issue-in-sound-ac97_bus.c.patch total: 0 errors, 0 warnings, 12 lines checked 0001-sound-Fixed-line-limit-issue-in-sound-ac97_bus.c.patch has no obvious style problems and is ready for submission. $
Dirty: 8 kB
Unevictable: 4 kB 0.1
Unevictable: 4 kB
The Unevictable LRU infrastructure addresses the following classes of unevictable pages: + page owned by ram disks or ramfs + page mapped into SHM_LOCKed shared memory regions + page mapped into VM_LOCKED [mlock()ed] vmas
Least Recently Used (LRU): discards the least recently used items first. This algorithm requires keeping track of what was used when, which is expensive if one wants to make sure the algorithm always discards the least recently used item. General implementations of this technique require to keep "age bits" for cache-lines and track the "Least Recently Used" cache-line based on age-bits. In such implementation, every time a cache-line is used, the age of all other cache-lines changes. LRU is actually a family of caching algorithms with members including: 2Q by Theodore Johnson and Dennis Shasha and LRU/K by Pat O'Neil, Betty O'Neil and Gerhard Weikum.
Hugetlb pages are also unevictable. Hugepages are already implemented in a way that these pages don't reside on the LRU and hence are not iterated over during the vmscan. So there is no need to move around these pages across different LRU's. We just account these pages as unevictable for correct statistics.
The Unevictable LRU adds an additional LRU list to track unevictable pages and to hide these pages from vmscan. This mechanism is based on a patch by Larry Woodman of Red Hat to address several scalability problems with page reclaim in Linux. The problems have been observed at customer sites on large memory x86_64 systems. For example, a non-numal x86_64 platform with 128GB of main memory will have over 32 million 4k pages in a single zone. When a large fraction of these pages are not evictable for any reason [see below], vmscan will spend a lot of time scanning the LRU lists looking for the small fraction of pages that are evictable. This can result in a situation where all cpus are spending 100% of their time in vmscan for hours or days on end, with the system completely unresponsive.
logger—0.6.xml
[daemon.log]Every daemon without a separate facility logs to daemon.log. The priority of log events is not relevent.[debug]File debug has messages useful for debugging.The priority of log events are not relevent.[dmesg] After the kernel has booted, all kernel messages are written to dmesg for later reference.This file is not rotated and only exists for a single boot cycle before being overwritten.Note that the choice of the name is a little unfortunate, as the dmesg command prints the current kernel log ring buffer,which is continuously updated and new kernel events are logged.These messages are written to kern.log; The dmesg file is not modified until the next restart of the system.[kern.log] Log messages with the kern facility end up in this file.The contents are mostly what the kernel spits out,after being formatted by klogd.[lpr.log]Log messages with the lpr facility end up in this file.
[mail.log] Log entries related to the mail system(using the mail facility) go into this file. For easier parsing by scripts,mail log entries are also written to mail.info, mail.warn,and mail.err,according to their priority. Unfortunately,Debian's default MTA,exim4, does not use this file.[messages]Pretty much everything that is not an error or a trivial log entry,and not related to authentication,daemons ,cron(or other automatic schedulers),mail,and news goes here.
btmp auth.log syslog boot
btmp shows a log of the file /var/log/btmp, which contains all the bad login attempts. auth.log receives log entries related to authentication,and other events that are critical to privacy or security issues. everything not related to authentication end up in syslog file. syslog is the catch-all log file on a debian system. log messages produced during the initialization sequence will be logged to boot.
proc asound devices 0.2
$cat /proc/asound/devices 2: : timer 3: : sequencer 4: [ 0- 2]: digital audio capture 5: [ 0- 1]: digital audio playback 6: [ 0- 1]: digital audio capture 7: [ 0- 0]: digital audio playback 8: [ 0- 0]: digital audio capture 9: [ 0- 0]: hardware dependent 10: [ 0] : control $
devices
Lists the ALSA native device mappings.
A music sequencer is a musical application or a device designed to play back musical notation. The original kind of sequencer is now known as a step sequencer to distinguish it from the modern kind, which records a musician playing notes.
GNUsound - A sound editor for Linux/x86. It supports multiple tracks, multiple outputs, and 8, 16, or 24/32 bit samples. It can read a number of audio formats through libaudiofile, and saves them as WAV. GNU sound
Digital audio uses pulse-code modulation and digital signals for sound reproduction. This includes analog-to-digital conversion (ADC), digital-to-analog conversion (DAC), storage, and transmission. In effect, the system commonly referred to as digital is in fact a discrete-time, discrete-level analog of a previous electrical analog. While modern systems can be quite subtle in their methods, the primary usefulness of a digital system is the ability to store, retrieve and transmit signals without any loss of quality.
Intel's use of the phrase audio codec refers to signals being encoded/decoded to/from analog audio from/to digital audio, thus actually a combined audio AD/DA-converter. This should not be confused with a codec in the sense of converting from one binary format to another, such as an audio (MP3) or video (Xvid) codec in a media player.
A timer is a specialized type of clock. A timer can be used to control the sequence of an event or process. Whereas a stopwatch counts upwards from zero for measuring elapsed time, a timer counts down from a specified time interval, like an hourglass. Timers can be mechanical, electromechanical, electronic (quartz), or even software as all modern computers include digital timers of one kind or another. When the set period expires some timers simply indicate so (e.g., by an audible signal), while others operate electrical switches, such as a time switch, which cuts electrical power.
proc filesystem with alsa.
$cat /proc/asound/cards
0 [NVidia ]: HDA-Intel - HDA NVidia
HDA NVidia at 0xf5000000 irq 22
$
The HD-audio component consists of two parts: the controller chip and the codec chips on the HD-audio Linux provides a single driver for all controllers, snd-hda-intel. Although the driver name contains a word of a well-known hardware vendor, it's not specific to it but for all controller chips by other companies. Since the HD-audio controllers are supposed to be compatible, the single snd-hda-driver should work in most cases.
Reference/Source:
Linux kernel documentation 2.6.32 related.
advanced linux sound architecture
The ALC883 series 7.1+2 Channel High Definition Audio (HDA) codecs are compliant with Microsoft's UAA (Universal Audio Architecture). The ALC883 series provide 10 DAC channels that simultaneously support 7.1 sound playback, plus 2 channels of independent stereo sound output (multiple streaming) through the front panel stereo output. Flexible mixing, mute, and fine gain control functions provide a complete integrated audio solution for home entertainment PCs. A modem (modulator-demodulator) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. Modems can be used over any means of transmitting analog signals, from driven diodes to radio. In electronics, modulation is the process of varying one or more properties of a high frequency periodic waveform, called the carrier signal, with respect to a modulating signal. This is done in a similar fashion as a musician may modulate a tone (a periodic waveform) from a musical instrument by varying its volume, timing and pitch.
acpi with proc
AC Adapter in Proc Filesystem
Alternating current (AC) adapters are used to power or charge many common electronic devices, such as mobile phones, laptop computers, or external hard drives. An AC adapter changes AC power from an electrical outlet into the type of power or voltage that an electronic device needs to work. Typically, each device has a designated adapter that is pre-set to the proper voltage conversion. For this reason, among others, AC adapters generally are not interchangeable.
$cat /proc/acpi/ac_adapter/ACAD/state
state: on-line
$
ACAD is the name of the adapter.
Beautiful Work 