Re: [PATCH 0/2] ALSA: hdsp, hdspm: Fix unlocked control_register updates in MIDI paths

[Takashi Iwai <tiwai@suse.de>]

On Fri, 06 Nov 2026 21:50:45 +0100,
Yifei Gao wrote:
> 
> 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

Applied both patches to for-next branch now.  Thanks.


Takashi