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Takashi Sakamoto 51db452df0 Revert "ALSA: echoaudio: purge contradictions between dimension matrix members and total number of members" 
This reverts commit 275353bb68 to fix a regression which can abort
'alsactl' program in alsa-utils due to assertion in alsa-lib.

alsactl: control.c:2513: snd_ctl_elem_value_get_integer: Assertion `idx < sizeof(obj->value.integer.value) / sizeof(obj->value.integer.value[0])' failed.

alsactl: control.c:2976: snd_ctl_elem_value_get_integer: Assertion `idx < ARRAY_SIZE(obj->value.integer.value)' failed.

This commit is a band-aid. In a point of usage of ALSA control interface,
the drivers still bring an issue that they prevent userspace applications
to have a consistent way to parse each levels of the dimension information
via ALSA control interface.

Let me investigate this issue. Current implementation of the drivers
have three control element sets with dimension information:
 * 'Monitor Mixer Volume' (type: integer)
 * 'VMixer Volume' (type: integer)
 * 'VU-meters' (type: boolean)

Although the number of elements named as 'Monitor Mixer Volume' differs
depending on drivers in this group, it can be calculated by macros
defined by each driver (= (BX_NUM - BX_ANALOG_IN) * BX_ANALOG_IN). Each
of the elements has one member for value and has dimension information
with 2 levels (= BX_ANALOG_IN * (BX_NUM - BX_ANALOG_IN)). For these
elements, userspace applications are expected to handle the dimension
information so that all of the elements construct a matrix where the
number of rows and columns are represented by the dimension information.

The same way is applied to elements named as 'VMixer Volume'. The number
of these elements can also be calculated by macros defined by each
drivers (= PX_ANALOG_IN * BX_ANALOG_IN). Each of the element has one
member for value and has dimension information with 2 levels
(= BX_ANALOG_IN * PX_ANALOG_IN). All of the elements construct a matrix
with the dimension information.

An element named as 'VU-meters' gets a different way in a point of
dimension information. The element includes 96 members for value. The
element has dimension information with 3 levels (= 3 or 2 * 16 * 2). For
this element, userspace applications are expected to handle the dimension
information so that all of the members for value construct a matrix
where the number of rows and columns are represented by the dimension
information. This is different from the way for the former.

As a summary, the drivers were not designed to produce a consistent way to
parse the dimension information. This makes it hard for general userspace
applications such as amixer to parse the information by a consistent way,
and actually no userspace applications except for 'echomixer' utilize the
dimension information. Additionally, no drivers excluding this group use
the information.

The reverted commit was written based on the latter way. A commit
860c1994a7 ('ALSA: control: add dimension validator for userspace
elements') is written based on the latter way, too. The patch should be
reconsider too in the same time to re-define a consistent way to parse the
dimension information.

Reported-by: Mark Hills <mark@xwax.org>
Reported-by: S. Christian Collins <s.chriscollins@gmail.com>
Fixes: 275353bb68 ('ALSA: echoaudio: purge contradictions between dimension matrix members and total number of members')
Cc: <stable@vger.kernel.org> # v4.8+
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-10-02 14:30:43 +02:00
arch Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-08-26 09:06:28 -07:00
block blk-mq-debugfs: Add names for recently added flags 2017-08-25 08:07:44 -06:00
certs modsign: add markers to endif-statements in certs/Makefile 2017-07-14 11:01:37 +10:00
crypto crypto: authencesn - Fix digest_null crash 2017-07-18 17:01:11 +08:00
Documentation Merge remote-tracking branches 'asoc/topic/wm8524', 'asoc/topic/wm8804' and 'asoc/topic/zte' into asoc-next 2017-09-01 12:13:19 +01:00
drivers IOMMU Fixes for Linux v4.13-rc6 2017-08-27 17:10:34 -07:00
firmware firmware/Makefile: force recompilation if makefile changes 2017-05-08 17:15:10 -07:00
fs Merge branch 'akpm' (patches from Andrew) 2017-08-25 18:02:27 -07:00
include ALSA: hda - program ICT bits to support HBR audio 2017-09-20 12:01:01 +02:00
init random: do not ignore early device randomness 2017-07-12 16:26:00 -07:00
ipc ipc: add missing container_of()s for randstruct 2017-08-02 17:16:12 -07:00
kernel Minor page waitqueue cleanups 2017-08-27 13:55:12 -07:00
lib kernel/watchdog: Prevent false positives with turbo modes 2017-08-18 12:35:02 +02:00
mm Avoid page waitqueue race leaving possible page locker waiting 2017-08-27 16:25:09 -07:00
net Two nfsd bugfixes, neither 4.13 regressions, but both potentially 2017-08-25 17:27:26 -07:00
samples samples/bpf: fix bpf tunnel cleanup 2017-07-31 22:02:47 -07:00
scripts Kbuild fixes for v4.13 2017-08-24 14:22:27 -07:00
security Now that IPC and other changes have landed, enable manual markings for 2017-07-19 08:55:18 -07:00
sound Revert "ALSA: echoaudio: purge contradictions between dimension matrix members and total number of members" 2017-10-02 14:30:43 +02:00
tools NTB bug fixes to address an incorrect ntb_mw_count reference in the NTB 2017-08-27 17:01:54 -07:00
usr ramfs: clarify help text that compression applies to ramfs as well as legacy ramdisk. 2017-07-06 16:24:30 -07:00
virt KVM/ARM Fixes for v4.13-rc4 2017-08-03 17:59:58 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support to generate LLVM assembly files 2017-04-25 08:13:52 +09:00
.mailmap power supply and reset changes for the v4.12 series (part 2) 2017-05-12 12:02:21 -07:00
COPYING
CREDITS avr32: remove support for AVR32 architecture 2017-05-01 09:27:15 +02:00
Kbuild kbuild: Consolidate header generation from ASM offset information 2017-04-13 05:43:37 +09:00
Kconfig
MAINTAINERS Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-08-20 09:07:56 -07:00
Makefile Linux 4.13-rc7 2017-08-27 17:20:40 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README 

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.