Hi, On Wed, Mar 24, 2021 at 06:42:53AM +0100, David Henningsson wrote: > diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h > index 535a7229e1d9..f33076755025 100644 > --- a/include/uapi/sound/asound.h > +++ b/include/uapi/sound/asound.h > @@ -736,12 +736,28 @@ struct snd_rawmidi_info { > unsigned char reserved[64]; /* reserved for future use */ > }; > > +enum { > + SNDRV_RAWMIDI_FRAMING_NONE = 0, > + SNDRV_RAWMIDI_FRAMING_TSTAMP_MONOTONIC_RAW, > + SNDRV_RAWMIDI_FRAMING_LAST = SNDRV_RAWMIDI_FRAMING_TSTAMP_MONOTONIC_RAW, > +}; In C language specification, enumeration is for value of int storage. In my opinion, int type should be used for the framing member, perhaps. (I think you can easily understand my insistent since you're Rust programmer.) I note that in UAPI of Linux kernel, we have some macros to represent system clocks; e.g. CLOCK_REALTIME, CLOCK_MONOTONIC: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/uapi/linux/time.h#n46 We can use the series of macro, instead of defining the specific enumerations. However I have one concern that the 'None' value cannot be zero in the case since CLOCK_REALTIME is zero. This is a bit inconvenient since we need initializer function in both of kernel space and user space... For the idea to record system timestamp when drivers call helper function to put MIDI message bytes into intermediate buffer in hardware/software IRQ context, I have some concerns and I'll post another message to thread, later. Regards Takashi Sakamoto