Re: [PATCH] ALSA: pcm: Allow HW_REFINE queries with mapped buffers

[Takashi Iwai <tiwai@suse.de>]

On Wed, 04 Nov 2026 01:40:25 +0100,
Vincent Cloutier wrote:
> 
> From: Vincent Cloutier <vincent@cloutier.co>
> 
> PulseAudio 16.1 queries supported formats after configuring and mapping
> a PCM buffer. Sharing HW_PARAMS' state checker with HW_REFINE causes
> these queries to fail with -EBADFD because a non-OSS stream has active
> buffer mappings. PulseAudio then fails to create its sinks and sources.
> 
> Make the mmap restriction optional in the shared state checker. Keep it
> for HW_PARAMS, which can reconfigure the mapped buffer, but skip it for
> HW_REFINE, which only refines the caller's constraint structure. Keep
> the stream-state checks and buffer access locking for native, compat
> and legacy refinement ioctls rather than bypassing their wrapper.
> Leave the accepted stream states unchanged.
> 
> On Librem 5, both L5 and Modem cards reproduce the failure for playback
> and capture: refinement succeeds before setup and after RW setup, but
> fails after MMAP setup in PREPARED state. With this change, all eight
> cases pass, PulseAudio starts normally and audible playback works.
> The reproducer does not start streams or transfer audio data.
> 
> Fixes: ad28d2f607d1 ("ALSA: pcm: Serialize and check HW_REFINE ioctls")
> Link: https://lore.kernel.org/linux-sound/41a2e39a-5637-8afa-f84f-f79e63b3b56e@xenosoft.de/
> Link: https://lore.kernel.org/linux-sound/874idyx9n6.wl-tiwai@suse.de/
> Assisted-by: OpenCode:GPT-6.1 Sol
> Signed-off-by: Vincent Cloutier <vincent@cloutier.co>

Applied now.  Thanks.


Takashi