linux.git/include/sound/timer.h, branch v6.18.21

ALSA: timer: Replace tasklet with work

2020-09-09T16:32:52+00:00

The tasklet is an old API that should be deprecated, usually can be
converted to another decent API.  In ALSA core timer API, the
callbacks can be offlined to a tasklet when a flag is set in the timer
backend.  It can be achieved gracefully with a work queued in the
high-prio system workqueue.

This patch replaces the usage of tasklet in ALSA timer API with a
simple work.  Currently the tasklet feature is used only in the system
timer and hrtimer backends, so both are patched to use the new flag
name SNDRV_TIMER_HW_WORK, too.

Link: https://lore.kernel.org/r/20200903104131.21097-3-tiwai@suse.de
Signed-off-by: Takashi Iwai

ALSA: Replace timespec with timespec64

2019-12-11T21:06:14+00:00

Since timespec is not year 2038 safe on 32bit system, and we need to
convert all timespec variables to timespec64 type for sound subsystem.

This patch is used to do preparation for following patches, that will
convert all structures defined in uapi/sound/asound.h to use 64-bit
time_t.

Signed-off-by: Baolin Wang 
Signed-off-by: Arnd Bergmann

ALSA: timer: Fix possible race at assigning a timer instance

2019-11-08T13:52:44+00:00

When a new timer instance is created and assigned to the active link
in snd_timer_open(), the caller still doesn't (can't) set its callback
and callback data.  In both the user-timer and the sequencer-timer
code, they do manually set up the callbacks after calling
snd_timer_open().  This has a potential risk of race when the timer
instance is added to the already running timer target, as the callback
might get triggered during setting up the callback itself.

This patch tries to address it by changing the API usage slightly:

- An empty timer instance is created at first via the new function
  snd_timer_instance_new().  This object isn't linked to the timer
  list yet.
- The caller sets up the callbacks and others stuff for the new timer
  instance.
- The caller invokes snd_timer_open() with this instance, so that it's
  linked to the target timer.

For closing, do similarly:

- Call snd_timer_close().  This unlinks the timer instance from the
  timer list.
- Free the timer instance via snd_timer_instance_free() after that.

Signed-off-by: Takashi Iwai 
Link: https://lore.kernel.org/r/20191107192008.32331-4-tiwai@suse.de
Signed-off-by: Takashi Iwai

ALSA: timer: Make snd_timer_close() returning void

2019-11-08T13:52:43+00:00

The function doesn't return any useful value, so let's make it void to
be clearer.

Signed-off-by: Takashi Iwai 
Link: https://lore.kernel.org/r/20191107192008.32331-3-tiwai@suse.de
Signed-off-by: Takashi Iwai

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Richard Fontana 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman

ALSA: timer: Limit max instances per timer

2017-11-06T09:41:24+00:00

Currently we allow unlimited number of timer instances, and it may
bring the system hogging way too much CPU when too many timer
instances are opened and processed concurrently.  This may end up with
a soft-lockup report as triggered by syzkaller, especially when
hrtimer backend is deployed.

Since such insane number of instances aren't demanded by the normal
use case of ALSA sequencer and it merely  opens a risk only for abuse,
this patch introduces the upper limit for the number of instances per
timer backend.  As default, it's set to 1000, but for the fine-grained
timer like hrtimer, it's set to 100.

Reported-by: syzbot
Tested-by: Jérôme Glisse 
Cc: 
Signed-off-by: Takashi Iwai

ALSA: timer: Introduce disconnect op to snd_timer_instance

2016-01-21T16:51:42+00:00

Instead of the previous ugly hack, introduce a new op, disconnect, to
snd_timer_instance object for handling the wake up of pending tasks
more cleanly.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=109431
Signed-off-by: Takashi Iwai

[ALSA] Changed Jaroslav Kysela's e-mail from perex@suse.cz to perex@perex.cz

2007-10-16T14:51:18+00:00

Signed-off-by: Jaroslav Kysela

[ALSA] Unregister device files at disconnection

2006-09-23T08:36:58+00:00

Orignally proposed by Sam Revitch .
Unregister device files at disconnection to avoid the futher accesses.
Also, the dev_unregister callback is removed and replaced with the
combination of disconnect + free.
A new function snd_card_free_when_closed() is introduced, which is
used in USB disconnect callback.

Signed-off-by: Takashi Iwai 
Signed-off-by: Jaroslav Kysela

[ALSA] Remove xxx_t typedefs: Timer

2006-01-03T11:17:34+00:00

Modules: RTC timer driver,Timer Midlevel

Remove xxx_t typedefs from the core timer.

Signed-off-by: Takashi Iwai