kernel-hacking-2024-linux-s.../sound
Thomas Gleixner f2ff7147c6 ALSA: pcsp: Make hrtimer forwarding more robust
The hrtimer callback pcsp_do_timer() prepares rearming of the timer with
hrtimer_forward(). hrtimer_forward() is intended to provide a mechanism to
forward the expiry time of the hrtimer by a multiple of the period argument
so that the expiry time greater than the time provided in the 'now'
argument.

pcsp_do_timer() invokes hrtimer_forward() with the current timer expiry
time as 'now' argument. That's providing a periodic timer expiry, but is
not really robust when the timer callback is delayed so that the resulting
new expiry time is already in the past which causes the callback to be
invoked immediately again. If the timer is delayed then the back to back
invocation is not really making it better than skipping the missed
periods. Sound is distorted in any case.

Use hrtimer_forward_now() which ensures that the next expiry is in the
future. This prevents hogging the CPU in the timer expiry code and allows
later on to remove hrtimer_forward() from the public interfaces.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: alsa-devel@alsa-project.org
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20210923153339.623208460@linutronix.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-09-28 10:58:08 +02:00
..
ac97 bus: Make remove callback return void 2021-07-21 11:53:42 +02:00
aoa Kbuild updates for v5.15 2021-09-03 15:33:47 -07:00
arm ALSA: pxa2xx: Use managed PCM buffer allocation 2021-08-04 08:08:21 +02:00
atmel
core ALSA: rawmidi: introduce SNDRV_RAWMIDI_IOCTL_USER_PVERSION 2021-09-23 09:26:40 +02:00
drivers ALSA: pcsp: Make hrtimer forwarding more robust 2021-09-28 10:58:08 +02:00
firewire ALSA: firewire-motu: fix truncated bytes in message tracepoints 2021-09-21 18:48:32 +02:00
hda
i2c
isa ALSA: gus: Fix repeated probe for ISA interwave card 2021-09-07 11:40:08 +02:00
mips
oss
parisc parisc architecture updates for kernel 5.15: 2021-09-02 13:16:00 -07:00
pci ALSA: hda/cs8409: Setup Dolphin Headset Mic as Phantom Jack 2021-09-16 12:24:46 +02:00
pcmcia
ppc
sh
soc ASoC: Fixes for v5.15 2021-09-21 18:42:14 +02:00
sparc
spi
synth
usb ALSA: usb-audio: Unify mixer resume and reset_resume procedure 2021-09-13 15:00:31 +02:00
virtio
x86 ALSA: memalloc: Correctly name as WC 2021-08-04 08:07:58 +02:00
xen
ac97_bus.c
Kconfig
last.c
Makefile
sound_core.c