sound updates for 4.6-rc1
After a heavy storm by syzkaller in 4.5 cycle, we have relatively few
changes in the core at this time while a lot of changes are found in
the driver side, unsurprisingly. Below are some highlights:
ALSA core:
- A few more hardening in ALSA timer codes
- An extension of sequencer API for advertising the card / pid
- Small fixes in compress-offload and jack layers
HD-audio:
- Dynamic PCM assignment in HDMI/DP codec; preparation for upcoming
DP-MST support
- Lots of code refactoring for sharing with ASoC SKL driver
- Regression fixes for Intel HDMI/DP
- Fixups for CX20724 codec, Lenovo AiO
USB-audio:
- Add quirk_alias option to make quirk debugging easier
- Fixes for possible Oops by malformed firmware
Firewire:
- Add support for FW-1804 in tascam driver
- Improvements / changes in card registration, multi stream handling,
etc for DICE
- Lots of code refactoring
ASoC:
- Enhancements of still ongoing topology API
- Lots of commits for Intel Skylake support including HDMI support
- A few Intel Atom driver updates for recent devices
- Lots of improvements to the Renesas drivers
- Capture support for Qualcomm drivers
- Support for TI DaVinci DRA7xxx devices
- New machine drivers for Freescale systems with Cirrus CODECs,
Mediatek systems with RT5650 CODECs
- New CPU drivers for Allwinner S/PDIF controllers
- New CODEC drivers for Maxim MAX9867 and MAX98926 and Realtek RT5514
ALSA: hda - Fix mutex deadlock at HDMI/DP hotplug
The recent change in HD-audio HDMI/DP codec driver for allowing the
dynamic PCM binding introduced a new spec->pcm_mutex. One of the
protected area by this mutex is hdmi_present_sense(). As reported by
Intel CI tests, unfortunately, the new mutex causes a deadlock when
the hotplug/unplug is triggered during the codec is in runtime
suspend. The buggy code path is like the following:
hdmi_unsol_event() -> ...
-> hdmi_present_sense()
==> ** here taking pcm_mutex
-> hdmi_present_sense_via_verbs()
-> snd_hda_power_up_pm() -> ... (runtime resume calls)
-> generic_hdmi_resume()
-> hdmi_present_sense()
==> ** here taking pcm_mutex again!
As we can see here, the problem is that the mutex is taken before
snd_hda_power_up_pm() call that triggers the runtime resume. That is,
the obvious solution is to move the power up/down call outside the
mutex; it is exactly what this patch provides.
The patch also clarifies why this bug wasn't caught beforehand. We
used to have the i915 audio component for hotplug for all Intel chips,
and in that code path, there is no power up required but the
information is taken directly from the graphics side. However, we
recently switched back to the old method for some old Intel chips due
to regressions, and now the deadlock issue is surfaced.
Fixes: a76056f2e57e ('ALSA: hda - hdmi dynamically bind PCM to pin when monitor hotplug')
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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