Kai Vehmanen 840c7109c7 ALSA: hda: avoid write to STATESTS if controller is in reset ... [ Upstream commit b37a15188e ] The snd_hdac_bus_reset_link() contains logic to clear STATESTS register before performing controller reset. This code dates back to an old bugfix in commit e8a7f136f5 ("[ALSA] hda-intel - Improve HD-audio codec probing robustness"). Originally the code was added to azx_reset(). The code was moved around in commit a41d122449 ("ALSA: hda - Embed bus into controller object") and ended up to snd_hdac_bus_reset_link() and called primarily via snd_hdac_bus_init_chip(). The logic to clear STATESTS is correct when snd_hdac_bus_init_chip() is called when controller is not in reset. In this case, STATESTS can be cleared. This can be useful e.g. when forcing a controller reset to retry codec probe. A normal non-power-on reset will not clear the bits. However, this old logic is problematic when controller is already in reset. The HDA specification states that controller must be taken out of reset before writing to registers other than GCTL.CRST (1.0a spec, 3.3.7). The write to STATESTS in snd_hdac_bus_reset_link() will be lost if the controller is already in reset per the HDA specification mentioned. This has been harmless on older hardware. On newer generation of Intel PCIe based HDA controllers, if configured to report issues, this write will emit an unsupported request error. If ACPI Platform Error Interface (APEI) is enabled in kernel, this will end up to kernel log. Fix the code in snd_hdac_bus_reset_link() to only clear the STATESTS if the function is called when controller is not in reset. Otherwise clearing the bits is not possible and should be skipped. Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com> Link: https://lore.kernel.org/r/20211012142935.3731820-1-kai.vehmanen@linux.intel.com Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Sasha Levin <sashal@kernel.org>		2021-10-27 09:51:41 +02:00
..
ext	ALSA: hda: prevent undefined shift in snd_hdac_ext_bus_get_link()	2020-11-18 18:27:53 +01:00
array.c	ALSA: hda: Fix krealloc() with __GFP_ZERO usage	2016-08-03 15:17:22 +02:00
hda_bus_type.c	ALSA: hda - Advertise MODALIAS in uevent	2015-10-20 10:15:53 +02:00
hdac_bus.c	ALSA: hda: Fix potential race in unsol event handler	2020-10-01 13:12:44 +02:00
hdac_controller.c	ALSA: hda: avoid write to STATESTS if controller is in reset	2021-10-27 09:51:41 +02:00
hdac_device.c	ALSA: hda: fix a runtime pm issue in SOF when integrated GPU is disabled	2020-09-23 10:46:27 +02:00
hdac_i915.c	ALSA: hda: Drop useless WARN_ON()	2018-01-02 20:31:04 +01:00
hdac_regmap.c	ALSA: hdac_regmap - fix the register access for runtime PM	2016-06-17 14:01:06 +02:00
hdac_stream.c	ALSA: hda - Avoid tricky macros	2017-04-03 08:42:43 +02:00
hdac_sysfs.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
hdmi_chmap.c	ALSA: hda: Use scnprintf() for printing texts for sysfs/procfs	2020-02-28 16:35:51 +01:00
Kconfig	ALSA: HDAC: move SND_HDA_PREALLOC_SIZE to core	2015-06-16 17:40:38 +02:00
local.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
Makefile	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
trace.c
trace.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00