[Mesa-dev] egl/android: fence_fd being forced to -1

[Rob Clark]

On Thu, Jun 15, 2017 at 12:04 PM, Tapani Pälli <tapani.palli at intel.com> wrote:
> On 06/15/2017 06:52 PM, Rob Clark wrote:
>>
>> On Thu, Jun 15, 2017 at 9:59 AM, Eric Engestrom
>> <eric.engestrom at imgtec.com> wrote:
>>>
>>> On Thursday, 2017-06-15 13:27:06 +0000, Marathe, Yogesh wrote:
>>>>
>>>> Hello,
>>>>
>>>> I'm tyring to run flatland native app on android. It apparantly fails
>>>> because of a fence issue.
>>>> while debuging further it is observed that droid_window_enqueue_buffer()
>>>> is forcing
>>>> fence_fd =-1.
>>
>> Yogesh, can you describe a bit more what "fails" means?  What sequence
>> of gl calls, for example, is it making?
>
>
>
> The problem described shortly: Flatland uses timestamps from Fence objects
> for calculating time (using getSignalTime API) and in case of having -1 from
> producer (Mesa) we will end up having same timestamp for startFence and
> endFence (since both are Fence::NO_FENCE) and thus flatland will keep
> running forever as it thinks no time has been passed between 2 fences. It is
> stuck in a loop where it tries to find how many frames are required so that
> driver will spend certain amount of time doing it.
>

hmm, any idea what the getSignalTime() API sits on top of?  I don't
think we have such a capability with fence fd's..

BR,
-R