linux/sound/pci/hda
Mohan Kumar ed4d0a4aaf ALSA: hda/tegra: Add 100us dma stop delay
Tegra HDA has audio data buffer for upto tens of frames, this buffer
can help to avoid underflow. HW will keep issuing new data fetch
request when buffers are not full and current BDL is not done. When SW
disable DMA RUN bit for a stream, HW can't cancel the already issued data
fetch request and hence it can't stop DMA. HW has to wait for all issued
data fetch request get data returned before it stops DMA.

This HW behavior is not in sync with HDA spec which says DMA RUN bit
should be cleared within 1 audio frame. For Tegra, DMA RUN bit was
active for more than one audio frame, due to this the timeout in
snd_hdac_stream_sync function is not helping. When Stream reset set
and clear happens during DMA RUN bit active state it results in Memory
Decode error.

Unfortunately, there is no way to detect when these data accesses have
completed, but testing has shown that a 100us delay between Stream reset
set and clear operation for Tegra avoids the memory decode error.
Therefore, adding a 100us dma stop delay.

Signed-off-by: Mohan Kumar <mkumard@nvidia.com>
Link: https://lore.kernel.org/r/20200805095221.5476-4-mkumard@nvidia.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-08-05 12:28:14 +02:00
..
ca0132_regs.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 32 2019-05-24 17:27:10 +02:00
hda_auto_parser.c ALSA: hda - let hs_mic be picked ahead of hp_mic 2020-06-25 15:00:45 +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: Use fallthrough pseudo-keyword 2020-07-09 13:01:29 +02:00
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 ASoC: Updates for v5.9 2020-08-03 14:41:43 +02:00
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_controller.c ALSA: hda: Enable sync-write operation as default for all controllers 2020-06-19 12:05:02 +02:00
hda_controller.h Merge branch 'for-next' into for-linus 2020-08-03 08:10:08 +02:00
hda_eld.c ALSA: hda: Use scnprintf() for printing texts for sysfs/procfs 2020-02-18 10:15:41 +01:00
hda_generic.c ALSA: Replace the word "slave" in vmaster API 2020-07-20 10:10:47 +02:00
hda_generic.h ALSA: Replace the word "slave" in vmaster API 2020-07-20 10:10:47 +02:00
hda_hwdep.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 32 2019-05-24 17:27:10 +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_intel.c Revert "ALSA: hda: call runtime_allow() for all hda controllers" 2020-08-03 09:28:41 +02:00
hda_intel.h ALSA: hda: Release resources at error in delayed probe 2020-04-13 18:02:36 +02:00
hda_jack.c ALSA: hda: correct kernel-doc parameter descriptions 2020-01-14 07:47:44 +01:00
hda_jack.h ALSA: hda - Add DP-MST jack support 2019-11-19 11:51:07 +01:00
hda_local.h ALSA: Replace the word "slave" in vmaster API 2020-07-20 10:10:47 +02:00
hda_proc.c ALSA: hda: More constifications 2020-01-05 16:14:32 +01:00
hda_sysfs.c ALSA: hda: Use scnprintf() for printing texts for sysfs/procfs 2020-02-18 10:15:41 +01:00
hda_tegra.c ALSA: hda/tegra: Add 100us dma stop delay 2020-08-05 12:28:14 +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
Kconfig ALSA: hda/hdmi: Add Intel silent stream support 2020-07-07 12:42:35 +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
patch_analog.c ALSA: hda/analog - Minor optimization for SPDIF mux connections 2020-01-16 17:29:17 +01:00
patch_ca0110.c ALSA: hda: Unify get_response handling 2019-12-13 14:36:52 +01:00
patch_ca0132.c ALSA: hda/ca0132 - Fix AE-5 microphone selection commands. 2020-08-03 08:12:17 +02:00
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: Use fallthrough pseudo-keyword 2020-07-09 13:01:29 +02:00
patch_hdmi.c ALSA: hda/hdmi: Add quirk to force connectivity 2020-08-04 20:54:36 +02:00
patch_realtek.c Merge branch 'for-next' into for-linus 2020-08-03 08:10:08 +02:00
patch_si3054.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 32 2019-05-24 17:27:10 +02:00
patch_sigmatel.c ALSA: Replace the word "slave" in vmaster API 2020-07-20 10:10:47 +02:00
patch_via.c ALSA: hda: Manage concurrent reg access more properly 2020-01-13 13:40:41 +01:00
thinkpad_helper.c ALSA: hda/realtek: Use the new vmaster mute LED helper 2020-06-18 13:23:49 +02:00