[PATCH v1 0/4] ALSA: compress_offload: Add 64-bit safe timestamp API

[George Verhaegen]

From: Joris Verhaegen <verhaegen at google.com>

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 introduces a parallel, 64-bit safe API to solve
this problem while maintaining perfect backward compatibility with the
existing UAPI. A new pointer64 operation and corresponding ioctls
are added to allow the kernel to track counters using u64 and expose
these full-width values to user-space.

The series is structured as follows:

Patch 1: Introduces the new internal pointer64 op, refactors the
core logic 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.

Patch 4: Implements the new .pointer64 operation in various ASoC
drivers that support compress offload.

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, and no regressions were observed
when using the legacy API.

Thanks,
George (Joris) Verhaegen

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

---

Joris Verhaegen (4):
  ALSA: compress_offload: Add 64-bit safe timestamp infrastructure
  ALSA: compress_offload: Add SNDRV_COMPRESS_TSTAMP64 ioctl
  ALSA: compress_offload: Add SNDRV_COMPRESS_AVAIL64 ioctl
  ASoC: codecs: Implement 64-bit pointer operation

 include/sound/compress_driver.h               |   3 +
 include/sound/soc-component.h                 |   5 +
 include/sound/soc-dai.h                       |   6 +
 include/uapi/sound/compress_offload.h         |  32 +++
 sound/core/compress_offload.c                 | 210 ++++++++++++++----
 sound/soc/codecs/cs47l15.c                    |   1 +
 sound/soc/codecs/cs47l24.c                    |   1 +
 sound/soc/codecs/cs47l35.c                    |   1 +
 sound/soc/codecs/cs47l85.c                    |   1 +
 sound/soc/codecs/cs47l90.c                    |   1 +
 sound/soc/codecs/cs47l92.c                    |   1 +
 sound/soc/codecs/wm5102.c                     |   1 +
 sound/soc/codecs/wm5110.c                     |   1 +
 sound/soc/codecs/wm_adsp.c                    |  53 ++++-
 sound/soc/codecs/wm_adsp.h                    |   3 +
 .../intel/atom/sst-mfld-platform-compress.c   |  17 +-
 sound/soc/intel/atom/sst-mfld-platform.h      |   2 +
 sound/soc/intel/atom/sst/sst_drv_interface.c  |  43 +++-
 sound/soc/qcom/qdsp6/q6asm-dai.c              |  41 +++-
 sound/soc/soc-component.c                     |  20 ++
 sound/soc/soc-compress.c                      |  21 ++
 sound/soc/soc-dai.c                           |  14 ++
 sound/soc/sof/compress.c                      |  44 +++-
 sound/soc/sprd/sprd-pcm-compress.c            |  28 ++-
 sound/soc/sprd/sprd-pcm-dma.h                 |   2 +-
 sound/soc/uniphier/aio-compress.c             |  40 +++-
 26 files changed, 503 insertions(+), 89 deletions(-)

-- 
2.50.0.727.gbf7dc18ff4-goog