[alsa-devel] [ALSA patch] [PATCH - alsa-lib 0/4] Add pcm_file input file support for MMAP

Takashi Iwai tiwai at suse.de
Wed May 22 16:25:22 CEST 2019


On Tue, 21 May 2019 15:32:26 +0200,
Adam Miartus wrote:
> 
> implement overwriting read buffer with input file in case of
> RW_NONINTERLEAVED and MMAP access modes for alsa file plugin
> 
> first two patches introduce a helper function for copying data from
> input file to readi and readn buffers for user. to facilitate this
> snd_pcm_areas_from_buf and snd_pcm_areas_from_bufs with
> snd_pcm_areas_copy is used. Previous readi behaviour in corner
> case of input file EOF is changed (more in patch comment).
> 
> Patch 3,4 introduce new api callback mmap_begin to ease overwritting
> mmaped buffer in case of MMAP access.
> 
> Adam Miartus (4):
>   pcm_file: add support for infile reading in non interleaved mode
>   pcm_file: use snd_pcm_file_areas_read_infile for readi
>   pcm: add mmap_begin callback to snd_pcm_fast_ops_t api
>   pcm_file: add infile read support for mmap mode

Thanks for resubmission.  Now I merged the first two patches, as they
are safe and good fixes.

The patches 3 and 4 are still pending, although I'm inclined to take
them for now.  Someone might have a better idea without the extra base
ops change.

In anyway, the patch 3 can be a bit simplified; the extra NULL
initialization is superfluous, so you can drop those lines.

Oh, BTW, at the next time to submit a patch set, please try to keep
the threading.  Usually git-send-email creates thread automatically
when you send the whole patches in a shot.


Takashi


More information about the Alsa-devel mailing list