On Wed, 13 Nov 2019 18:19:56 +0100,
Arnd Bergmann wrote:
>
> On Wed, Nov 13, 2019 at 6:04 PM Takashi Iwai <tiwai@xxxxxxx> wrote:
> >
> > On Wed, 13 Nov 2019 17:51:57 +0100,
> > Arnd Bergmann wrote:
> > >
> > > On Wed, Nov 13, 2019 at 5:40 PM Takashi Iwai <tiwai@xxxxxxx> wrote:
> > > > On Wed, 13 Nov 2019 15:32:44 +0100, Arnd Bergmann wrote:
> > >
> > > > > We had discussed alternatives for this one last time, and decided
> > > > > to go with the solution I posted here. The main alternative would
> > > > > be to change the 'timespec' in snd_timer_tread to a fixed-length
> > > > > structure based on two 'long' members. This would avoid the
> > > > > need to match the command with the time_t type, but the cost would
> > > > > be requiring CLOCK_MONOTONIC timestamps to avoid the
> > > > > overflow, and changing all application source code that requires
> > > > > the type to be compatible with 'timespec'.
> > > >
> > > > Fair enough.
> > > >
> > > > One thing I forgot to mention: when we add/modify the ioctl or ABI, we
> > > > need to increment the protocol version, e.g. SNDRV_PCM_VERSION to
> > > > indicate user-space the supported ABI. Please change these in your
> > > > next patches, too.
> > >
> > > Just to confirm: this should be a simple one-line patch at the end of the
> > > series like
> > >
> > > diff --git a/tools/include/uapi/sound/asound.h
> > > b/tools/include/uapi/sound/asound.h
> > > index df1153cea0b7..72e8380c6dcd 100644
> > > --- a/include/uapi/sound/asound.h
> > > +++ b/include/uapi/sound/asound.h
> > > @@ -154,7 +154,7 @@ struct snd_hwdep_dsp_image {
> > > * *
> > > *****************************************************************************/
> > >
> > > -#define SNDRV_PCM_VERSION SNDRV_PROTOCOL_VERSION(2, 0, 14)
> > > +#define SNDRV_PCM_VERSION SNDRV_PROTOCOL_VERSION(2, 0, 15)
> > >
> > > typedef unsigned long snd_pcm_uframes_t;
> > > typedef signed long snd_pcm_sframes_t;
> > >
> > > right? Most other kernel interfaces have no version numbering, so
> > > I don't know what policy you have here.
> >
> > I don't mind much about that, so it's up to you -- we can fold this
> > change into the patch that actually adds or modifies the ioctl, too.
>
> I've added the patch below to the end of the series now, will repost
> the series after no more comments come in for this version.
> Having a single patch to update the version seems better than updating
> it multiple times with each patch touching the ABI in this series.
>
> Arnd
>
> commit b83a3eaece9b445f897a6f5ac2a903f2566a0e9d
> Author: Arnd Bergmann <arnd@xxxxxxxx>
> Date: Wed Nov 13 17:49:14 2019 +0100
>
> ALSA: bump uapi version number
>
> Change SNDRV_PCM_VERSION to indicate the addition of the time64
> version of the mmap interface and these ioctl commands:
>
> SNDRV_PCM_IOCTL_SYNC
> SNDRV_RAWMIDI_IOCTL_STATUS
> SNDRV_PCM_IOCTL_STATUS
> SNDRV_PCM_IOCTL_STATUS_EXT
> SNDRV_TIMER_IOCTL_TREAD
> SNDRV_TIMER_IOCTL_STATUS
>
> 32-bit applications built with 64-bit time_t require both the headers
> and the running kernel to support at least API version 2.0.15. When
> built with earlier kernel headers, some of these may not work
> correctly, so applications are encouraged to fail compilation like
>
> #if SNDRV_PCM_VERSION < SNDRV_PROTOCOL_VERSION(2, 0, 15)
> extern int __fail_build_for_time_64[sizeof(long) - sizeof(time_t)];
> #endif
>
> or provide their own updated copy of the header file.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
>
> diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h
> index 25dbf71fa667..5cddfe62c97a 100644
> --- a/include/uapi/sound/asound.h
> +++ b/include/uapi/sound/asound.h
> @@ -156,7 +156,7 @@ struct snd_hwdep_dsp_image {
> * *
> *****************************************************************************/
>
> -#define SNDRV_PCM_VERSION SNDRV_PROTOCOL_VERSION(2, 0, 14)
> +#define SNDRV_PCM_VERSION SNDRV_PROTOCOL_VERSION(2, 0, 15)
>
> typedef unsigned long snd_pcm_uframes_t;
> typedef signed long snd_pcm_sframes_t;
I wasn't clear enough. Each ALSA device API has a protocol version,
not only PCM, so we need updating SNDRV_RAWMIDI_VERSION and
SNDRV_TIMER_VERSION as well.
thanks,
Takashi
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