lkml.org 
[lkml]   [2019]   [Jan]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [alsa-devel] [PATCH v9 4/4] sound/usb: Use Media Controller API to share media resources
    From
    Date
    On 1/11/19 7:59 AM, Hans Verkuil wrote:
    > On 1/11/19 3:57 PM, shuah wrote:
    >> On 12/19/18 6:51 AM, Takashi Iwai wrote:
    >>> On Tue, 18 Dec 2018 18:59:39 +0100,
    >>> shuah@kernel.org wrote:
    >>>>
    >>>> From: Shuah Khan <shuah@kernel.org>
    >>>>
    >>>> Media Device Allocator API to allows multiple drivers share a media device.
    >>>> This API solves a very common use-case for media devices where one physical
    >>>> device (an USB stick) provides both audio and video. When such media device
    >>>> exposes a standard USB Audio class, a proprietary Video class, two or more
    >>>> independent drivers will share a single physical USB bridge. In such cases,
    >>>> it is necessary to coordinate access to the shared resource.
    >>>>
    >>>> Using this API, drivers can allocate a media device with the shared struct
    >>>> device as the key. Once the media device is allocated by a driver, other
    >>>> drivers can get a reference to it. The media device is released when all
    >>>> the references are released.
    >>>>
    >>>> Change the ALSA driver to use the Media Controller API to share media
    >>>> resources with DVB, and V4L2 drivers on a AU0828 media device.
    >>>>
    >>>> The Media Controller specific initialization is done after sound card is
    >>>> registered. ALSA creates Media interface and entity function graph nodes
    >>>> for Control, Mixer, PCM Playback, and PCM Capture devices.
    >>>>
    >>>> snd_usb_hw_params() will call Media Controller enable source handler
    >>>> interface to request the media resource. If resource request is granted,
    >>>> it will release it from snd_usb_hw_free(). If resource is busy, -EBUSY is
    >>>> returned.
    >>>>
    >>>> Media specific cleanup is done in usb_audio_disconnect().
    >>>>
    >>>> Signed-off-by: Shuah Khan <shuah@kernel.org>
    >>>
    >>> Feel free to take my ack regarding the sound stuff:
    >>>    Reviewed-by: Takashi Iwai <tiwai@suse.de>
    >>>
    >>>
    >>> Thanks!
    >>>
    >>> Takashi
    >>>
    >>
    >> Hi Mauro,
    >>
    >> Any update on this patch series?
    >
    > I'm planning to process this series for 5.1. Haven't gotten around to it yet,
    > but I expect to do this next week.
    >
    > Still going through all the pending patches after the Christmas period :-)
    >
    > Regards,
    >
    > Hans
    >

    Hans,

    Thanks for a quick reply. No worries. I am recovering from the Christmas
    and vacation myself. :)

    thanks,
    -- Shuah


    \
     
     \ /
      Last update: 2019-01-11 16:04    [W:3.092 / U:0.012 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site