Go to file
Takashi Iwai 24d0c9f0e7 ALSA: usb-audio: Limit max buffer and period sizes per time
In the previous fix, we increased the max buffer bytes from 1MB to 4MB
so that we can use bigger buffers for the modern HiFi devices with
higher rates, more channels and wider formats.  OTOH, extending this
has a concern that too big buffer is allowed for the lower rates, less
channels and narrower formats; when an application tries to allocate
as big buffer as possible, it'll lead to unexpectedly too huge size.

Also, we had a problem about the inconsistent max buffer and period
bytes for the implicit feedback mode when both streams have different
channels.  This was fixed by the (relatively complex) patch to reduce
the max buffer and period bytes accordingly.

This is an alternative fix for those, a patch to kill two birds with
one stone (*): instead of increasing the max buffer bytes blindly and
applying the reduction per channels, we simply use the hw constraints
for the buffer and period "time".  Meanwhile the max buffer and period
bytes are set unlimited instead.

Since the inconsistency of buffer (and period) bytes comes from the
difference of the channels in the tied streams, as long as we care
only about the buffer (and period) time, it doesn't matter; the buffer
time is same for different channels, although we still allow higher
buffer size.  Similarly, this will allow more buffer bytes for HiFi
devices while it also keeps the reasonable size for the legacy
devices, too.

As of this patch, the max period and buffer time are set to 1 and 2
seconds, which should be large enough for all possible use cases.

(*) No animals were harmed in the making of this patch.

Fixes: 98c27add5d ("ALSA: usb-audio: Cap upper limits of buffer/period bytes for implicit fb")
Fixes: fee2ec8cce ("ALSA: usb-audio: Increase max buffer size")
Link: https://lore.kernel.org/r/20220412130740.18933-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-04-13 09:10:56 +02:00
arch ASoC: Rename tlv320aic31xx-micbias.h as tlv320aic31xx.h 2022-01-24 13:31:52 +00:00
block bitmap patches for 5.17-rc1 2022-01-23 06:20:44 +02:00
certs certs: Fix build error when CONFIG_MODULE_SIG_KEY is empty 2022-01-23 00:08:44 +09:00
crypto lib/crypto: add prompts back to crypto libraries 2022-01-18 13:03:55 +01:00
Documentation ALSA: hda/realtek: Add alc256-samsung-headphone fixup 2022-03-22 21:51:02 +01:00
drivers ASoC: Updates for v5.18 2022-03-21 16:19:21 +01:00
fs bitmap patches for 5.17-rc1 2022-01-23 06:20:44 +02:00
include ALSA: memalloc: Add fallback SG-buffer allocations for x86 2022-04-13 07:48:53 +02:00
init lib/stackdepot: allow optional init and stack_table allocation by kvmalloc() 2022-01-22 08:33:37 +02:00
ipc proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
kernel ftrace: Fix s390 breakage from sorting mcount tables 2022-01-23 08:07:02 +02:00
lib bitmap patches for 5.17-rc1 2022-01-23 06:20:44 +02:00
LICENSES
mm bitmap patches for 5.17-rc1 2022-01-23 06:20:44 +02:00
net bitmap patches for 5.17-rc1 2022-01-23 06:20:44 +02:00
samples Merge branch 'akpm' (patches from Andrew) 2022-01-20 10:41:01 +02:00
scripts Devicetree fixes for v5.17, take 1: 2022-01-22 09:52:17 +02:00
security fs.idmapped.v5.17 2022-01-11 14:26:55 -08:00
sound ALSA: usb-audio: Limit max buffer and period sizes per time 2022-04-13 09:10:56 +02:00
tools kselftest: alsa: fix spelling mistake "desciptor" -> "descriptor" 2022-02-08 08:24:42 +01:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-01-22 21:48:45 +09:00
virt Generic: 2022-01-22 09:40:01 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap Merge branch 'kvm-pi-raw-spinlock' into HEAD 2022-01-19 12:14:02 -05:00
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS ASoC: Updates for v5.18 2022-03-21 16:19:21 +01:00
Makefile Linux 5.17-rc1 2022-01-23 10:12:53 +02:00
README

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.