[alsa-devel] [PATCH 0/7] ALSA: USB-audio: Support Zoom R16 playback

[Takashi Iwai]

On Thu, 15 Oct 2015 12:57:30 +0200,
Ricard Wanderlof wrote:
> 
> The Zoom R16 has a nonstandard playback format where each isochronous
> packet contains a length descriptor in the first four bytes. Curiously,
> capture data does not contain this and requires no quirk.
> 
> The quirk involves adding the extra length descriptor whenever outgoing
> isochronous packets are generated, both in pcm.c (outgoing audio) and
> endpoint.c (silent data). The calculation for the max packet size in
> endpoint.c is also affected.
> 
> This patch series refactors some code in pcm.c and endpoint.c before the
> actual quirk implementation. A commit then cleans up the entry in the
> quirks table.
> 
> Tested with a Zoom R16, both separately using arecord and aplay (8 channel
> capture and 2 channel playback, respectively), as well as capture and
> playback together together using the Ardour digitial audio workstation
> application.  The R24 reportedly is compatible with the R16, but I don't
> have access to one so I can't test it, and consequently the patch series
> only mentions the R16.
> 
> Also tested using an Edirol UA-5 in both class compliant (16-bit) and
> "advanced" (24 bit, forces the use of quirks) modes in order to do some
> form of regression testing.

The changes look OK, the only point to be fixed would be the use of
__le32 for a variable as kbuild bot suggested.  However, there are way
too few description in the changelog.  The patches 1-4 are only code
shuffling, so it's OK (though, better to mention more explicitly that
there is no functional change).  But patches 5-6 are the core part,
and this doesn't contain *why* this is needed.  The irony is that you
put so many good texts in the cover letter.

So, please make the changelogs more readable and enjoyable instead of
the cover letter texts.  The cover letter won't be included in the
commits, after all.


thanks,

Takashi

> 
> Ricard Wanderlof (7):
>   Break out copying to urb from prepare_playback_urb()
>   Also move out hwptr_done wrap from prepare_playback_urb()
>   Break out creation of silent urbs from prepare_outbound_urb()
>   Add offset parameter to copy_to_urb()
>   Add quirk for Zoom R16 playback
>   Adjust max packet size calculation for tx_length_quirk
>   Remove mixer entry from Zoom R16/24 quirk
> 
>  sound/usb/card.h         |  1 +
>  sound/usb/endpoint.c     | 73 +++++++++++++++++++++++++++++++++--------------
>  sound/usb/pcm.c          | 74 +++++++++++++++++++++++++++++++++++++-----------
>  sound/usb/quirks-table.h | 14 +++------
>  sound/usb/quirks.c       |  3 ++
>  sound/usb/stream.c       |  1 +
>  sound/usb/usbaudio.h     |  1 +
>  7 files changed, 119 insertions(+), 48 deletions(-)
> 
> -- 
> 2.1.4
>