On Fri, 25 Jul 2025 13:42:42 +0200, Joris Verhaegen wrote:

The current compress offload timestamping API relies on struct snd_compr_tstamp, whose cumulative counters like copied_total are defined as __u32. On long-running high-resolution audio streams, these 32-bit counters can overflow, causing incorrect availability calculations.

This patch series transitions to a 64-bit safe API to solve the problem while maintaining perfect backward compatibility with the existing UAPI. The pointer operation is reworked to use a new timestamp struct with 64-bit fields for the cumulative counters, named snd_compr_tstamp64. ASoC drivers are updated to use the 64-bit structures. Corresponding ioctls are added to expose them to user-space.

The series is structured as follows:

Patch 1: Updates the pointer op, refactors the core logic and ASoC drivers to use it, and defines the new UAPI structs.

Patch 2: Exposes the SNDRV_COMPRESS_TSTAMP64 ioctl.

Patch 3: Exposes the corresponding SNDRV_COMPRESS_AVAIL64 ioctl.

This series has been tested on a Pixel 9 device. All compress offload use cases, including long-running playback, were verified to work correctly with the new 64-bit API.

Thanks, Joris (George) Verhaegen

Signed-off-by: Joris Verhaegen <verhaegen@google.com>

Through a quick glance, the patches look OK, but since it's too late for 6.17 merge window for such a non-trivial core API change, so I'll postpone the merge for 6.18. thanks, Takashi