Re: [PATCH v4 0/2] firmware_loader/ALSA: Fix TAS2781 async firmware teardown

[Takashi Iwai <tiwai@suse.de>]

On Tue, 05 May 2026 13:18:15 +0200,
Cássio Gabriel wrote:
> 
> TAS2781 HDA I2C and SPI queue RCA firmware loading with
> request_firmware_nowait() during component bind. The firmware loader
> keeps the callback module pinned and holds a device reference, but it
> does not provide a way for drivers to cancel or synchronize the queued
> callback before tearing down driver-private state.
> 
> Add a small firmware-loader helper to cancel or synchronize async firmware
> requests, then use it from TAS2781 HDA unbind before controls and DSP state
> are removed.
> 
> No hardware runtime test was available.
> 
> Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>
> ---
> Changes in v4:
> - Use spin_lock_irq() in the worker and cancel paths, which run from
>   sleepable contexts.
> - Fold kfree(fw_work) into firmware_work_free().
> - Keep irqsave in the request path so GFP_ATOMIC callers do not depend on
>   IRQ state assumptions.
> - Link to v3: https://patch.msgid.link/20260501-alsa-hda-tas2781-fw-callback-teardown-v3-0-8d9f873b97bd@gmail.com
> 
> Changes in v3:
> - Keep request_firmware_nowait() manually managed instead of making the
>   existing API implicitly devres-managed.
> - Track scheduled async firmware work in an internal list protected by a
>   spinlock so request_firmware_nowait_cancel() can find and synchronize a
>   pending request without weakening the GFP_ATOMIC caller contract.
> - Match pending requests by device, callback context and callback function
>   instead of matching by callback alone.
> - Avoid the devres_add() / schedule_work() ordering race pointed out in
>   review.
> - Leave devres-managed support for a separate devm_request_firmware_nowait()
>   API if needed.
> - Link to v2: https://patch.msgid.link/20260430-alsa-hda-tas2781-fw-callback-teardown-v2-0-2c7d89cb3175@gmail.com
> 
> Changes in v2:
> - Add request_firmware_nowait_cancel() in the firmware loader instead of
>   tracking the callback lifetime locally in the TAS2781 HDA driver.
> - Keep the TAS2781 change to a cancel/sync call in I2C and SPI unbind.
> - Drop the unrelated cached kcontrol pointer cleanup from the previous
>   local-driver version.
> - Link to v1: https://patch.msgid.link/20260430-alsa-hda-tas2781-fw-callback-teardown-v1-1-874367d6b41b@gmail.com
> 
> ---
> Cássio Gabriel (2):
>       firmware_loader: Add cancel helper for async requests
>       ALSA: hda/tas2781: Cancel async firmware request at unbind

I guess this could go via driver tree?  Or I can take both if I get an
ack, too.

In anyway, for the series:

Reviewed-by: Takashi Iwai <tiwai@suse.de>


thanks,

Takashi