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Takashi Iwai 0e279dcea0 ALSA: pcm: Fix refcount_inc() on zero usage
The recent rewrite of PCM link lock management introduced the refcount
in snd_pcm_group object, managed by the kernel refcount_t API.  This
caused unexpected kernel warnings when the kernel is built with
CONFIG_REFCOUNT_FULL=y.  As the warning line indicates, the problem is
obviously that we start with refcount=0 and do refcount_inc() for
adding each PCM link, while refcount_t API doesn't like refcount_inc()
performed on zero.

For adapting the proper refcount_t usage, this patch changes the logic
slightly:
- The initial refcount is 1, assuming the single list entry
- The refcount is incremented / decremented at each PCM link addition
  and deletion
- ... which allows us concentrating only on the refcount as a release
  condition

Fixes: f57f3df03a ("ALSA: pcm: More fine-grained PCM link locking")
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=204221
Reported-and-tested-by: Duncan Overbruck <kernel@duncano.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-07-19 15:47:00 +02:00
arch powerpc fixes for 5.2 #7 2019-06-30 11:20:52 +08:00
block block, bfq: fix operator in BFQQ_TOTALLY_SEEKY 2019-06-25 11:38:08 -06:00
certs treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
crypto treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
Documentation Merge branch 'asoc-5.3' into asoc-next 2019-07-06 12:25:26 +01:00
drivers Merge branch 'asoc-5.3' into asoc-next 2019-07-06 12:25:26 +01:00
fs XArray updates for 5.2-rc6 2019-06-29 17:14:57 +08:00
include ALSA: hda - Don't resume forcibly i915 HDMI/DP codec 2019-07-16 22:46:13 +02:00
init initramfs: fix populate_initrd_image() section mismatch 2019-06-29 16:43:45 +08:00
ipc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
kernel Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-06-30 11:19:17 +08:00
lib XArray updates for 5.2-rc6 2019-06-29 17:14:57 +08:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm mm, swap: fix THP swap out 2019-06-29 16:43:45 +08:00
net Two more NFS client fixes for Linux 5.2 2019-06-29 17:02:22 +08:00
samples samples: make pidfd-metadata fail gracefully on older kernels 2019-06-24 15:55:50 +02:00
scripts treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 505 2019-06-19 17:11:22 +02:00
security SPDX update for 5.2-rc6 2019-06-21 09:58:42 -07:00
sound ALSA: pcm: Fix refcount_inc() on zero usage 2019-07-19 15:47:00 +02:00
tools Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-06-29 19:39:17 +08:00
usr user/Makefile: Fix typo and capitalization in comment section 2018-12-11 00:18:03 +09:00
virt SPDX update for 5.2-rc6 2019-06-21 09:58:42 -07:00
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COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: Farewell Martin Schwidefsky 2019-05-31 10:14:11 +02:00
Kbuild Kbuild updates for v5.1 2019-03-10 17:48:21 -07:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS Merge branch 'asoc-5.3' into asoc-next 2019-07-06 12:25:26 +01:00
Makefile Linux 5.2-rc7 2019-06-30 11:25:36 +08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

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.