[PATCH 02/11] dma-buf/fence: add fence_array fences v6

[Sumit Semwal]

Hi Christian, Gustavo,

Thanks for these patches.

On 1 June 2016 at 20:55, Gustavo Padovan <gustavo at padovan.org> wrote:
> 2016-06-01 Christian König <deathsimple at vodafone.de>:
>
>> From: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
>>
>> struct fence_collection inherits from struct fence and carries a
>> collection of fences that needs to be waited together.
>>
>> It is useful to translate a sync_file to a fence to remove the complexity
>> of dealing with sync_files on DRM drivers. So even if there are many
>> fences in the sync_file that needs to waited for a commit to happen,
>> they all get added to the fence_collection and passed for DRM use as
>> a standard struct fence.
>>
>> That means that no changes needed to any driver besides supporting fences.
>>
>> fence_collection's fence doesn't belong to any timeline context, so
>> fence_is_later() and fence_later() are not meant to be called with
>> fence_collections fences.
>>
>> v2: Comments by Daniel Vetter:
>>       - merge fence_collection_init() and fence_collection_add()
>>       - only add callbacks at ->enable_signalling()
>>       - remove fence_collection_put()
>>       - check for type on to_fence_collection()
>>       - adjust fence_is_later() and fence_later() to WARN_ON() if they
>>       are used with collection fences.
>>
>> v3: - Initialize fence_cb.node at fence init.
>>
>>     Comments by Chris Wilson:
>>       - return "unbound" on fence_collection_get_timeline_name()
>>       - don't stop adding callbacks if one fails
>>       - remove redundant !! on fence_collection_enable_signaling()
>>       - remove redundant () on fence_collection_signaled
>>       - use fence_default_wait() instead
>>
>> v4 (chk): Rework, simplification and cleanup:
>>       - Drop FENCE_NO_CONTEXT handling, always allocate a context.
>>       - Rename to fence_array.
>>       - Return fixed driver name.
>>       - Register only one callback at a time.
>>       - Document that create function takes ownership of array.
>>
>> v5 (chk): More work and fixes:
>>       - Avoid deadlocks by adding all callbacks at once again.
>>       - Stop trying to remove the callbacks.
>>       - Provide context and sequence number for the array fence.
>>
>> v6 (chk): Fixes found during testing
>>       - Fix stupid typo in _enable_signaling().
>>
>> Signed-off-by: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
>> Signed-off-by: Christian König <christian.koenig at amd.com>
>> ---
>>  drivers/dma-buf/Makefile      |   2 +-
>>  drivers/dma-buf/fence-array.c | 127 ++++++++++++++++++++++++++++++++++++++++++
>>  include/linux/fence-array.h   |  72 ++++++++++++++++++++++++
>>  3 files changed, 200 insertions(+), 1 deletion(-)
>>  create mode 100644 drivers/dma-buf/fence-array.c
>>  create mode 100644 include/linux/fence-array.h
>
> This is working fine to me. Once the commit message is fixed:
>
> Reviewed-by: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
>
> You need to Cc Sumit here to decide who is picking these patches.
> It would be better to get them through the drm trees so we would need
> his Ack at least.
>
+1 on the commit message consistency change; post that, please feel
free to add my
Acked-by: Sumit Semwal <sumit.semwal at linaro.org>

for the 3 dma-buf/fences patches and request to take them via DRM tree
as rightly suggested by Gustavo.

>         Gustavo

BR,
Sumit.