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

[Vinod Koul <vkoul@kernel.org>]

On 11-07-25, 09:24, George Verhaegen wrote:
> From: Joris Verhaegen <verhaegen@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.

In your testing when did you observe the overflow condition?

> 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.

Please share patches for tinycompress support too, we need those to test
this

> 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@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

-- 
~Vinod