5d980fadf7
mixer(8)'s -a option is used to print information about all mixer devices in the system. To do this, it loops from 0 to mixer_get_nmixers(), and tries to open "/dev/mixer%d". However, this approach doesn't work when there are disabled/unregistered mixers in the system, or when an audio device simply doesn't have a mixer. mixer_get_nmixers() calls SNDCTL_SYSINFO and returns oss_sysinfo->nummixers, whose value is the number of currently _enabled_ mixers only. Taking the bug report mentioned below (277615) as an example, suppose a system with 8 mixer devices total, but 3 of them are either disabled or non-existent, which means they will not show up under /dev, meaning we have 5 enabled mixer devices, which is also what the value of oss_sysinfo->nummixers will be. What mixer(8) will do is loop from 0 to 5 (instead of 8), and start calling mixer_open() on /dev/mixer0, up to /dev/mixer4, and as is expected, the first call will fail right away, hence the error shown in the bug report. To fix this, modify oss_sysinfo->nummixers to hold the value of the maximum unit in the system, which, although not necessarily "correct", is more intuitive for applications that will want to use this value to loop through all mixer devices. Additionally, notify applications that a device is unavailable/unregistered instead of skipping it. The current implementations of SNDCTL_AUDIOINFO, SNDCTL_MIXERINFO and SNDCTL_CARDINFO break applications that expect to get information about a device that is skipped. Related discussion can be found here: https://reviews.freebsd.org/D45135#1029526 It has to be noted, that other applications, apart from mixer(8), suffer from this. PR: 277615 Sponsored by: The FreeBSD Foundation MFC after: 1 day Reviewed by: dev_submerge.ch Differential Revision: https://reviews.freebsd.org/D45256 |
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| .cirrus-ci | ||
| .github | ||
| bin | ||
| cddl | ||
| contrib | ||
| crypto | ||
| etc | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| stand | ||
| sys | ||
| targets | ||
| tests | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| .arcconfig | ||
| .arclint | ||
| .cirrus.yml | ||
| .clang-format | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| CONTRIBUTING.md | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| Makefile.libcompat | ||
| Makefile.sys.inc | ||
| ObsoleteFiles.inc | ||
| README.md | ||
| RELNOTES | ||
| UPDATING | ||
FreeBSD Source:
This is the top level of the FreeBSD source directory.
FreeBSD is an operating system used to power modern servers, desktops, and embedded platforms. A large community has continually developed it for more than thirty years. Its advanced networking, security, and storage features have made FreeBSD the platform of choice for many of the busiest web sites and most pervasive embedded networking and storage devices.
For copyright information, please see the file COPYRIGHT in this directory. Additional copyright information also exists for some sources in this tree - please see the specific source directories for more information.
The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree. See build(7), config(8), FreeBSD handbook on building userland, and Handbook for kernels for more information, including setting make(1) variables.
For information on the CPU architectures and platforms supported by FreeBSD, see the FreeBSD website's Platforms page.
For official FreeBSD bootable images, see the release page.
Source Roadmap:
| Directory | Description |
|---|---|
| bin | System/user commands. |
| cddl | Various commands and libraries under the Common Development and Distribution License. |
| contrib | Packages contributed by 3rd parties. |
| crypto | Cryptography stuff (see crypto/README). |
| etc | Template files for /etc. |
| gnu | Commands and libraries under the GNU General Public License (GPL) or Lesser General Public License (LGPL). Please see gnu/COPYING and gnu/COPYING.LIB for more information. |
| include | System include files. |
| kerberos5 | Kerberos5 (Heimdal) package. |
| lib | System libraries. |
| libexec | System daemons. |
| release | Release building Makefile & associated tools. |
| rescue | Build system for statically linked /rescue utilities. |
| sbin | System commands. |
| secure | Cryptographic libraries and commands. |
| share | Shared resources. |
| stand | Boot loader sources. |
| sys | Kernel sources (see sys/README.md). |
| targets | Support for experimental DIRDEPS_BUILD |
| tests | Regression tests which can be run by Kyua. See tests/README for additional information. |
| tools | Utilities for regression testing and miscellaneous tasks. |
| usr.bin | User commands. |
| usr.sbin | System administration commands. |
For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see FreeBSD Handbook.