Re: [PATCH v4 0/3] Media Device Allocator API

From: Shuah Khan
Date: Wed Nov 16 2016 - 09:39:49 EST


Sorry for the duplicates. Replying to catch bounced emails on the original
patch emails from git send-email

On 11/16/2016 07:29 AM, Shuah Khan wrote:
> Media Device Allocator API to allows multiple drivers share a media device.
> 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.
>
> Patches 0001 and 0002 are rebased to 4.9-rc4. Patch 0003 for snd-usb-audio
> is a rebase of the patch that was tested with the original Media Device
> Allocator patch series.
>
> snd-usb-audio patch includes the fixes found during 4.7-rc1 time in the
> original snd-usb-audio patch.
>
> Changes to patch 0001 since v3:
> - Fixed undefined reference to `__media_device_usb_init compile error when
> CONFIG_USB is disabled.
> - Fixed kernel paging error when accessing /dev/mediaX after rmmod of the
> module that owns the media_device. The fix bumps the reference count for
> the owner when second driver comes along to share the media_device. If
> au0828 owns the media_device, then snd_usb_audio will bump the refcount
> for au0828, so it won't get deleted and vice versa.
>
> Changes to patch 0002 since v2:
> - Updated media_device_delete() to pass in module name.
>
> Changes to patch 0003 since the last version in 4.7-rc1:
> - Included fixes to bugs found during testing.
> - Updated to use the Media Allocator API.
>
> This patch series has been tested with au0828 and snd-usb-audio drivers.
> Ran bind and unbind loop tests on each driver with mc_nextgen_test and
> media_device_test app loop tests while checking lsmod and dmesg.
>
> Please refer to tools/testing/selftests/media_tests/regression_test.txt
> for testing done on this series.
>
> Shuah Khan (3):
> media: Media Device Allocator API
> media: change au0828 to use Media Device Allocator API
> sound/usb: Use Media Controller API to share media resources
>
> drivers/media/Makefile | 3 +-
> drivers/media/media-dev-allocator.c | 146 +++++++++++++++
> drivers/media/usb/au0828/au0828-core.c | 12 +-
> drivers/media/usb/au0828/au0828.h | 1 +
> include/media/media-dev-allocator.h | 87 +++++++++
> sound/usb/Kconfig | 4 +
> sound/usb/Makefile | 2 +
> sound/usb/card.c | 14 ++
> sound/usb/card.h | 3 +
> sound/usb/media.c | 314 +++++++++++++++++++++++++++++++++
> sound/usb/media.h | 73 ++++++++
> sound/usb/mixer.h | 3 +
> sound/usb/pcm.c | 28 ++-
> sound/usb/quirks-table.h | 1 +
> sound/usb/stream.c | 2 +
> sound/usb/usbaudio.h | 6 +
> 16 files changed, 685 insertions(+), 14 deletions(-)
> create mode 100644 drivers/media/media-dev-allocator.c
> create mode 100644 include/media/media-dev-allocator.h
> create mode 100644 sound/usb/media.c
> create mode 100644 sound/usb/media.h
>