linux/sound/pci/hda
Takashi Iwai 88452da92b ALSA: hda: Use standard waitqueue for RIRB wakeup
The HD-audio CORB/RIRB communication was programmed in a way that was
documented in the reference in decades ago, which is essentially a
polling in the waiter side.  It's working fine but costs CPU cycles on
some platforms that support only slow communications.  Also, for some
platforms that had unreliable communications, we put longer wait time
(2 ms), which accumulate quite long time if you execute many verbs in
a shot (e.g. at the initialization or resume phase).

This patch attempts to improve the situation by introducing the
standard waitqueue in the RIRB waiter side instead of polling.  The
test results on my machine show significant improvements.  The time
spent for "cat /proc/asound/card*/codec#*" were changed like:

* Intel SKL + Realtek codec
  before the patch:
   0.00user 0.04system 0:00.10elapsed 40.0%CPU
  after the patch:
   0.00user 0.01system 0:00.10elapsed 10.0%CPU

* Nvidia GP107GL + Nvidia HDMI codec
  before the patch:
   0.00user 0.00system 0:02.76elapsed 0.0%CPU
  after the patch:
   0.00user 0.00system 0:00.01elapsed 17.0%CPU

So, for Intel chips, the total time is same, while the total time is
greatly reduced (from 2.76 to 0.01s) for Nvidia chips.
The only negative data here is the increase of CPU time for Nvidia,
but this is the unavoidable cost for faster wakeups, supposedly.

Link: https://lore.kernel.org/r/20191210145727.22054-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-12-10 18:22:46 +01:00
..
Kconfig ALSA: hda: add Intel DSP configuration / probe code 2019-10-23 06:31:37 +02:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ca0132_regs.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 32 2019-05-24 17:27:10 +02:00
hda_auto_parser.c ASoC: Updates for v5.4 2019-09-10 13:03:08 +02:00
hda_auto_parser.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 46 2019-05-24 17:27:12 +02:00
hda_beep.c ALSA: hda - Use standard device registration for beep 2019-01-29 18:28:09 +01:00
hda_beep.h ALSA: hda - Use standard device registration for beep 2019-01-29 18:28:09 +01:00
hda_bind.c ALSA: hda - Fix pending unsol events at shutdown 2019-10-28 12:44:28 +01:00
hda_codec.c Merge branch 'asoc-5.4' into asoc-next 2019-09-09 14:55:20 +01:00
hda_controller.c ALSA: hda: Use standard waitqueue for RIRB wakeup 2019-12-10 18:22:46 +01:00
hda_controller.h Merge branch 'asoc-5.4' into asoc-next 2019-09-09 14:55:20 +01:00
hda_controller_trace.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hda_eld.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 32 2019-05-24 17:27:10 +02:00
hda_generic.c ALSA: hda/realtek - Fix overridden device-specific initialization 2019-08-30 12:03:38 +02:00
hda_generic.h ALSA: hda/realtek - Fix overridden device-specific initialization 2019-08-30 12:03:38 +02:00
hda_hwdep.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 32 2019-05-24 17:27:10 +02:00
hda_intel.c ALSA: hda/hdmi - Fix duplicate unref of pci_dev 2019-12-10 18:20:31 +01:00
hda_intel.h ALSA: hda - Allow runtime PM for controller if component notifier is used 2019-08-27 16:37:50 +02:00
hda_intel_trace.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hda_jack.c ALSA: hda - Add DP-MST jack support 2019-11-19 11:51:07 +01:00
hda_jack.h ALSA: hda - Add DP-MST jack support 2019-11-19 11:51:07 +01:00
hda_local.h ALSA: hda - Expand pin_match function to match upcoming new tbls 2019-08-16 11:59:30 +02:00
hda_proc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 32 2019-05-24 17:27:10 +02:00
hda_sysfs.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
hda_tegra.c ALSA: hda: Direct MMIO accesses 2019-08-08 16:36:18 +02:00
hp_x360_helper.c ALSA: hda/realtek - Fixup for HP x360 laptops with B&O speakers 2018-05-29 22:33:37 +02:00
patch_analog.c ALSA: hda - Add laptop imic fixup for ASUS M9V laptop 2019-09-20 15:53:24 +02:00
patch_ca0110.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 32 2019-05-24 17:27:10 +02:00
patch_ca0132.c ALSA: hda/ca0132 - Fix possible workqueue stall 2019-11-05 14:44:12 +01:00
patch_cirrus.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 32 2019-05-24 17:27:10 +02:00
patch_cmedia.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 32 2019-05-24 17:27:10 +02:00
patch_conexant.c ALSA: hda - Add mute led support for HP ProBook 645 G4 2019-11-20 09:42:52 +01:00
patch_hdmi.c ALSA: hda: hdmi - Keep old slot assignment behavior for Intel platforms 2019-12-03 20:33:05 +01:00
patch_realtek.c ALSA: hda - fixup for the bass speaker on Lenovo Carbon X1 7th gen 2019-11-29 15:43:19 +01:00
patch_si3054.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 32 2019-05-24 17:27:10 +02:00
patch_sigmatel.c ALSA: hda/sigmatel - remove unused variable 'stac9200_core_init' 2019-08-13 17:44:48 +02:00
patch_via.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 32 2019-05-24 17:27:10 +02:00
thinkpad_helper.c ALSA: hda - Support led audio trigger 2018-11-28 23:25:22 +01:00