[PATCH 0/2] ALSA: hdsp, hdspm: Fix unlocked control_register updates in MIDI paths
From: Yifei Gao
Date: Fri Nov 06 2026 - 15:51:11 EST
hdsp and hdspm keep a software copy of the card's control register and
update it read-modify-write under the card lock, except in some MIDI
input paths, where concurrent updates can be lost.
In 2011, commit c0da00145f9a ("ALSA: hdspm - Fix locking in
snd_hdspm_midi_input_read") fixed the MIDI work side in hdspm. The
interrupt handler side was left unlocked, and hdsp has both problems.
Patch 1 fixes hdsp. Patch 2 fixes the remaining interrupt handler side
in hdspm.
Both issues were found by static analysis. The patches are
compile-tested only (W=1). I have no access to this hardware, so tests
on a real card would be very welcome.
Yifei Gao (2):
ALSA: hdsp: Serialize control_register updates in MIDI input paths
ALSA: hdspm: Take hdspm->lock when masking MIDI interrupts in IRQ
handler
sound/pci/rme9652/hdsp.c | 16 ++++++++++++----
sound/pci/rme9652/hdspm.c | 8 +++++---
2 files changed, 17 insertions(+), 7 deletions(-)
--
2.34.1